code: public function header_old($name = null, $value = null)
  	{
  		// Set
  		if ($value !== null)
  		{
  			if (is_array($value))
  				foreach ($value as $field => $val) $this->headers[$field] = $val;
  			else if (is_string($name))
  				$this->headers[$name] = $value;
  		}
  
  		// Get
  		return !$name ? $this->headers : ($this->headers[$name] ?? null);
  	}
docs: Get or set header
  
  @deprecated v0.2.5
  
  If both parameters are null all headers are returned
  otherwise the header identified by $name field is returned
  and if $value is not null the field value is updated
  
  @param string|array	$name	field name
  @param string|array	$value	header value or array of field => value to set
  
  @return string|array