public function addValue($part)
    {
        if (is_null($this->value)) {
            $this->value = $part;
        } else {
            $this->value = array_merge((array) $this->value, (array) $part);
        }
    }
public function addValue($part)
    {
        if (is_null($this->value)) {
            $this->value = $part;
        } else {
            $this->value = array_merge((array) $this->value, (array) $part);
        }
    }
public function addValue ( $ part ) { if ( is_null ( $ this -> value ) ) { $ this -> value = $ part ; } else { $ this -> value = array_merge ( ( array ) $ this -> value , ( array ) $ part ) ; } }
Adds a value to this parameter.

If the argument is specified as an array, all items will be added to the
parameter value list.

@param string|array $part
Adds a value to this parameter .