Extend this method to define fields of your choice.
3823
public function init()
    {
        $this->_init();

        if ($this->id_field) {
            $this->addField($this->id_field, [
                'system'    => true,
            ]);
        }
    }
1027053
def add_field(self, field, **kwargs):
        """"""
        getattr(self, self._private_fields_name).append(field)
        self._expire_cache(reverse=True)
        self._expire_cache(reverse=False)
1092132
def set_fields(self, fields=None, *fields_args, **fields_kwargs):
        
        if fields_args:
            fields = [fields]
            fields.extend(fields_args)
            for field_name in fields:
                self.set_field(field_name)

        elif fields_kwargs:
            fields = make_dict(fields, fields_kwargs)
            for field_name, field_val in fields.items():
                self.set_field(field_name, field_val)

        else:
            if isinstance(fields, Mapping):
                for field_name, field_val in fields.items():
                    self.set_field(field_name, field_val)

            else:
                for field_name in fields:
                    self.set_field(field_name)

        return self
13243
def fill_fields(self, **kwargs):
        """"""
        for name, value in kwargs.items():
            field = getattr(self, name)
            field.send_keys(value)
318200
public void setupFields()
    {
        FieldInfo field = null;
        field = new FieldInfo(this, ID, Constants.DEFAULT_FIELD_LENGTH, null, null);
        field.setDataClass(Integer.class);
        field = new FieldInfo(this, KEY, 128, null, null);
        field = new FieldInfo(this, VALUE, 255, null, null);
        field = new FieldInfo(this, COMMENT, 255, null, null);
    }
162079
def extend(self, values):
        """"""
        if self.asserted:
            raise RuntimeError("Fact already asserted")

        self._multifield.extend(values)
1361623
def extend(self, **attributes):
        
        for key, value in attributes.iteritems():
            if not hasattr(self, key):
                setattr(self, key, value)
990703
def add_fields(self, field_dict):
    
    for key, field in field_dict.items():
      self.add_field(key, field)
413511
public void addReadFields2(FieldSet readFields) {
		if(this.readFields2 == null) {
			this.readFields2 = new FieldSet(readFields);
		} else {
			this.readFields2.addAll(readFields);
		}
	}
536928
def field(name, **options)
      name = name.to_sym
      definitions[name] = options
      proxy.instance_eval do
        define_method(name) { fields[name] }
        define_method("#{name}=") { |value| fields[name] = value }
      end
    end
991469
def add_field(self, field):
        
        if not isinstance(field, fields.BaseField):
            raise ValueError('Argument "field" must be an instance of '
                             'BaseField')
        self.fields.add(field.name, field)
499636
public void setupFields()
    {
        FieldInfo field = null;
        field = new FieldInfo(this, ID, Constants.DEFAULT_FIELD_LENGTH, null, null);
        field.setDataClass(Integer.class);
        field.setHidden(true);
        field = new FieldInfo(this, LAST_CHANGED, Constants.DEFAULT_FIELD_LENGTH, null, null);
        field.setDataClass(Date.class);
        field.setHidden(true);
        field = new FieldInfo(this, DELETED, 10, null, new Boolean(false));
        field.setDataClass(Boolean.class);
        field.setHidden(true);
        field = new FieldInfo(this, CODE, 250, null, null);
        field = new FieldInfo(this, DESCRIPTION, 40, null, null);
        field = new FieldInfo(this, LOCATION, 128, null, null);
        field = new FieldInfo(this, TYPE, 20, null, null);
        field = new FieldInfo(this, BASE_RESOURCE_ID, Constants.DEFAULT_FIELD_LENGTH, null, null);
        field.setDataClass(Integer.class);
        field = new FieldInfo(this, CLASS_PROJECT_ID, Constants.DEFAULT_FIELD_LENGTH, null, null);
        field.setDataClass(Integer.class);
    }
592747
def add_field(self, name, default_value=None):
        """"""
        self._fields[name] = default_value

        def func(cluster):
            return self.get(name, cluster)

        setattr(self, name, func)
821780
@Override
	public void addField(final SchemaField field) {

		if (field instanceof FieldDefinition) {
			addField((FieldDefinition) field);
		} else if (field instanceof CopyFieldDefinition) {
			addCopyField((CopyFieldDefinition) field);
		}
	}
91084
public void setupFields()
    {
        FieldInfo field = null;
        field = new FieldInfo(this, ID, Constants.DEFAULT_FIELD_LENGTH, null, null);
        field.setDataClass(Integer.class);
        field.setHidden(true);
        field = new FieldInfo(this, LAST_CHANGED, Constants.DEFAULT_FIELD_LENGTH, null, null);
        field.setDataClass(Date.class);
        field.setHidden(true);
        field = new FieldInfo(this, DELETED, 10, null, new Boolean(false));
        field.setDataClass(Boolean.class);
        field.setHidden(true);
        field = new FieldInfo(this, CLASS_NAME, 40, null, null);
        field = new FieldInfo(this, BASE_CLASS_NAME, 40, null, null);
        field = new FieldInfo(this, CLASS_DESC, 255, null, null);
        field = new FieldInfo(this, CLASS_PROJECT_ID, Constants.DEFAULT_FIELD_LENGTH, null, null);
        field.setDataClass(Integer.class);
        field = new FieldInfo(this, CLASS_PACKAGE, 60, null, null);
        field = new FieldInfo(this, CLASS_SOURCE_FILE, 40, null, null);
        field = new FieldInfo(this, CLASS_TYPE, 20, null, null);
        field = new FieldInfo(this, CLASS_EXPLAIN, Constants.DEFAULT_FIELD_LENGTH, null, null);
        field = new FieldInfo(this, CLASS_HELP, Constants.DEFAULT_FIELD_LENGTH, null, null);
        field = new FieldInfo(this, CLASS_IMPLEMENTS, 60, null, null);
        field = new FieldInfo(this, SEE_ALSO, 32000, null, null);
        field = new FieldInfo(this, TECHNICAL_INFO, 32000, null, null);
        field = new FieldInfo(this, COPY_DESC_FROM, 50, null, null);
    }
748277
def _init_fields(self):
        """"""
        if self.opts.fields:
            available_field_names = self.set_class(self.opts.fields)
        else:
            available_field_names = self.set_class(self.declared_fields.keys())
            if self.opts.additional:
                available_field_names |= self.set_class(self.opts.additional)

        invalid_fields = self.set_class()

        if self.only is not None:
            # Return only fields specified in only option
            field_names = self.set_class(self.only)

            invalid_fields |= field_names - available_field_names
        else:
            field_names = available_field_names

        # If "exclude" option or param is specified, remove those fields.
        exclude_field_names = set(self.opts.exclude) | set(self.exclude)
        if exclude_field_names:
            # Note that this isn't available_field_names, since we want to
            # apply "only" for the actual calculation.
            field_names = field_names - exclude_field_names

            invalid_fields |= exclude_field_names - available_field_names

        if invalid_fields:
            message = 'Invalid fields for {}: {}.'.format(self, invalid_fields)
            raise ValueError(message)

        fields_dict = self.dict_class()
        for field_name in field_names:
            field_obj = self.declared_fields.get(field_name, ma_fields.Inferred())
            self._bind_field(field_name, field_obj)
            fields_dict[field_name] = field_obj

        dump_data_keys = [
            obj.data_key or name for name, obj in iteritems(fields_dict) if not obj.load_only
        ]
        if len(dump_data_keys) != len(set(dump_data_keys)):
            data_keys_duplicates = {x for x in dump_data_keys if dump_data_keys.count(x) > 1}
            raise ValueError(
                'The data_key argument for one or more fields collides '
                "with another field's name or data_key argument. "
                'Check the following field names and '
                'data_key arguments: {}'.format(list(data_keys_duplicates)),
            )

        load_attributes = [
            obj.attribute or name for name, obj in iteritems(fields_dict) if not obj.dump_only
        ]
        if len(load_attributes) != len(set(load_attributes)):
            attributes_duplicates = {x for x in load_attributes if load_attributes.count(x) > 1}
            raise ValueError(
                'The attribute argument for one or more fields collides '
                "with another field's name or attribute argument. "
                'Check the following field names and '
                'attribute arguments: {}'.format(list(attributes_duplicates)),
            )

        return fields_dict
18861
protected function set_field() {

		$properties = get_class_vars( __CLASS__ );

		// Some things must run before the others.
		$this->set_option_type();
		$this->set_settings();

		// Sanitize the properties, skipping the ones that have already run above.
		foreach ( $properties as $property => $value ) {
			if ( in_array( $property, [ 'option_name', 'option_type', 'settings' ], true ) ) {
				continue;
			}
			if ( method_exists( $this, 'set_' . $property ) ) {
				$method_name = 'set_' . $property;
				$this->$method_name();
			}
		}

		// Get all arguments with their values.
		$args = get_object_vars( $this );
		foreach ( array_keys( $args ) as $key ) {
			$args[ $key ] = $this->$key;
		}

		// Add the field to the static $fields variable properly indexed.
		Kirki::$fields[ $this->settings ] = $args;

	}