public function addHeader($header, $value = NULL)
	{
		if($header instanceof HttpHeaderInterface)
		{
			$n = strtolower($header->getFieldName());
			
			if(empty($this->headers[$n]))
			{
				$this->headers[$n] = [[(string)$header->getFieldName(), trim($header->getFieldValue())]];
			}
			else
			{
				$this->headers[$n][] = [(string)$header->getFieldName(), trim($header->getFieldValue())];
			}
		}
		else
		{
			$n = strtolower($header);
			
			if(empty($this->headers[$n]))
			{
				$this->headers[$n] = [[(string)$header, trim($value)]];
			}
			else
			{
				$this->headers[$n][] = [(string)$header, trim($value)];
			}
		}
		
		return $this;
	}
public function addHeader($header, $value = NULL)
	{
		if($header instanceof HttpHeaderInterface)
		{
			$n = strtolower($header->getFieldName());
			
			if(empty($this->headers[$n]))
			{
				$this->headers[$n] = [[(string)$header->getFieldName(), trim($header->getFieldValue())]];
			}
			else
			{
				$this->headers[$n][] = [(string)$header->getFieldName(), trim($header->getFieldValue())];
			}
		}
		else
		{
			$n = strtolower($header);
			
			if(empty($this->headers[$n]))
			{
				$this->headers[$n] = [[(string)$header, trim($value)]];
			}
			else
			{
				$this->headers[$n][] = [(string)$header, trim($value)];
			}
		}
		
		return $this;
	}
public function addHeader ( $ header , $ value = NULL ) { if ( $ header instanceof HttpHeaderInterface ) { $ n = strtolower ( $ header -> getFieldName ( ) ) ; if ( empty ( $ this -> headers [ $ n ] ) ) { $ this -> headers [ $ n ] = [ [ ( string ) $ header -> getFieldName ( ) , trim ( $ header -> getFieldValue ( ) ) ] ] ; } else { $ this -> headers [ $ n ] [ ] = [ ( string ) $ header -> getFieldName ( ) , trim ( $ header -> getFieldValue ( ) ) ] ; } } else { $ n = strtolower ( $ header ) ; if ( empty ( $ this -> headers [ $ n ] ) ) { $ this -> headers [ $ n ] = [ [ ( string ) $ header , trim ( $ value ) ] ] ; } else { $ this -> headers [ $ n ] [ ] = [ ( string ) $ header , trim ( $ value ) ] ; } } return $ this ; }
Add an HTTP header to the message.

@param mixed $header A header name or an instance of HttpHeaderInterface.
@param string $value
@return HttpMessage
Add an HTTP header to the message .