Removes observed css rule

@param string $rule
@return $this
354520
public function removeObservedCssRule($rule)
    {
        if (isset($this->observedCssRules[$rule])) {
            unset($this->observedCssRules[$rule]);
        }

        return $this;
    }
513981
public function addRules(array $rules)
    {
        foreach ($rules as $character => $replacement) {
            $this->addRule($character, $replacement);
        }

        return $this;
    }
786550
public function removeFilter($filter) {
		foreach ($this->filters as $key => $value) {
			if ($value['filter'] == $filter) {
				unset($this->filters[$key]);
			}
		}

		return $this;
	}
1261770
public function removeRev($relation)
        {
            if (isset($this->_rev[$relation])) {
                unset($this->_rev[$relation]);
            }

            return $this;
        }
1005737
public function removeProperty( ADT_CSS_Rule $rule, ADT_CSS_Property $property ){
		return $this->remove( $rule->getSelector(), $property->getKey() );
	}
402094
public function setRule($rule, $replacement)
    {
        if (is_array($rule)) {
            $this->rules = $rule;
            return $this;
        }

        $this->rules[$rule] = $replacement;
        return $this;
    }
547500
public function filterRules($rules)
    {
        foreach ($this->_behaviors as $name => $foo) {
            if (($behavior = $this->getBehavior($name)) instanceof \nineinchnick\usr\components\FormModelBehavior) {
                $rules = $behavior->filterRules($rules);
            }
        }

        return $rules;
    }
97818
public function removeRel($relation)
        {
            if (isset($this->_rel[$relation])) {
                unset($this->_rel[$relation]);
            }

            return $this;
        }
1266840
public function removeRuleBySelector( $selector ){
		foreach( $this->rules as $nr => $rule ){
			if( $selector == $rule->getSelector() ){
				unset( $this->rules[$nr] );
				return TRUE;
			}
		}
		return FALSE;
	}
824696
public function removeRule(HTML_QuickForm2_Rule $rule)
    {
        foreach ($this->rules as $i => $r) {
            if ($r[0] === $rule) {
                unset($this->rules[$i]);
                break;
            }
        }
        return $rule;
    }
468848
protected function isInlineDirective($rule)
    {
        foreach ($this->directiveArray() as $directive) {
            if (0 === strpos(mb_strtolower($rule), $directive . ':')) {
                return $directive;
            }
        }
        return false;
    }
440634
public function removeRule($ruleName)
    {
        if (isset($this->rules[$ruleName])) {
            unset($this->rules[$ruleName]);
            return true;
        }
        return false;
    }
267851
private function isRule($rule) {

		if(false === is_string($rule)) {
			return false;
		}

		$class = $this -> getRuleClass($rule);

		return true === class_exists($class);
	}
68492
public function extend(string $rule, string $ruleClass): Validator
	{
		$this->rules[$rule] = $ruleClass;

		return $this;
	}
960899
public function rules($rules)
    {
        foreach ($rules as $rule => $field) {
            if (is_array($field) && is_array($field[0])) {
                foreach ($field as $params) {
                    array_unshift($params, $rule);
                    call_user_func_array([$this, 'rule'], $params);
                }
            } else {
                $this->rule($rule, $field);
            }
        }
        return $this;
    }
873686
protected function applyRule($word, $rule)
    {
        return substr_replace($word, $rule[self::APPEND_STRING], strlen($word) - $rule[self::REMOVE_TOTAL]);        
    }
755224
public function addRule(RuleAbstract $rule)
    {
        // TODO Keyframes with duplicate identifiers do NOT cascade!
        // Last one overwrites previous ones.
        // @see https://developer.mozilla.org/en-US/docs/Web/CSS/@keyframes#Duplicate_resolution

        if ($rule instanceof KeyframesRuleSet) {
            $this->rules[] = $rule;
        } else {
            throw new \InvalidArgumentException(
                "Invalid rule instance. Instance of 'KeyframesRuleSet' expected."
            );
        }

        return $this;
    }