Determine whether the HeaderBag contains a header with $name,
case-insensitively.

@api

@param string $name
@return bool
505334
public function has($name)
    {
        Types::assert(['string' => [$name]]);

        return array_key_exists(strtolower($name), $this->headers);
    }
721938
public function has($name)
    {
        $tid = $this->getTid($name);
        if (!isset($this->_containers[$tid])) {
            return false;
        }
        return $this->_containers[$tid]->has($name);
    }
17565
public function __isset($name) {
        if (array_key_exists($name, self::$coursecatfields)) {
            return isset($this->$name);
        }
        return false;
    }
1242007
public function has($name, $index = 0)
    {
        $lowerName = strtolower($name);

        if (!array_key_exists($lowerName, $this->headers)) {
            return false;
        }

        if (func_num_args() < 2) {
            // index was not specified, so we only need to check that there is at least one header value set
            return (bool) count($this->headers[$lowerName]);
        }

        return array_key_exists($index, $this->headers[$lowerName]);
    }
530019
public function has($name)
    {
        $names = is_array($name) ? $name : func_get_args();

        foreach ($names as $value) {
            if (! $this->routes->hasNamedRoute($value)) {
                return false;
            }
        }

        return true;
    }
362933
public function has($name)
    {
        return isset($this->payload[$name]) || isset($this->map[ltrim($name, '/')]);
    }
1174875
private function getHeader($name)
    {
        if (isset($this->headers[$name])) {
            return $this->headers[$name];
        }
        return false;
    }
1024752
public function hasHtml(string $name) : bool
    {
        return $this->htmlContentAreas->any(function (HtmlContentArea $contentArea) use ($name) {
            return $contentArea->name === $name;
        });
    }
405667
public function hasExtra($name)
    {
        return isset($this->extras[$name]) || array_key_exists($name, $this->extras);
    }
1213534
public function hasMethod($name)
    {
        return method_exists($this, $name)
            || (isset($this->_hookTrait) && $this->hookHasCallbacks('method-'.$name))
            || $this->hasGlobalMethod($name);
    }
1230091
public function has($name)
    {
        foreach ($this->filters() as $filter) {
            if ($filter->id() === $name) {
                return true;
            }
        }

        return false;
    }
1112807
public function has(string $name) : bool
  {
    if (isset($this->all[$name])) return true;
    return false;
  }
22965
public function hasExtension($name)
    {
        return isset($this->extensions[$name]) || isset($this->extensionsByNs[$name]);
    }
808283
public function containsHeader(string $name, string $value = null): bool
    {
        if ($this->headers->contain($name)) {
            if (null !== $value) {
                return $value === $this->headers[$name];
            }

            return true;
        }

        return false;
    }
863307
public function __isset($name)
	{
		if (method_exists($this, 'get_' . $name) || isset($this->$name))
		{
			return true;
		}
		else
		{
			return false;
		}
	}
752880
public function hasColumn($name)
    {
        $name = $this->filterInputColumn($name);

        return in_array($name, $this->getFields());
    }
393856
public function hasGroup($name)
    {
        if ($name instanceof GroupInterface) {
            return $this->groups->contains($name);
        }

        return $this->groups->containsKey($name);
    }