public function setPrefix($prefix)
    {
        if (is_string($prefix) === false) {
            $msg = "The prefix argument must be a string.";
            throw new InvalidArgumentException($msg);
        } elseif ($prefix === '') {
            $msg = "The prefix argument must be a non-empty string.";
            throw new InvalidArgumentException($msg);
        } else {
            $this->prefix = $prefix;
        }
    }
public function setPrefix($prefix)
    {
        if (is_string($prefix) === false) {
            $msg = "The prefix argument must be a string.";
            throw new InvalidArgumentException($msg);
        } elseif ($prefix === '') {
            $msg = "The prefix argument must be a non-empty string.";
            throw new InvalidArgumentException($msg);
        } else {
            $this->prefix = $prefix;
        }
    }
public function setPrefix ( $ prefix ) { if ( is_string ( $ prefix ) === false ) { $ msg = "The prefix argument must be a string." ; throw new InvalidArgumentException ( $ msg ) ; } elseif ( $ prefix === '' ) { $ msg = "The prefix argument must be a non-empty string." ; throw new InvalidArgumentException ( $ msg ) ; } else { $ this -> prefix = $ prefix ; } }
Set the XML prefix of the mapping.

@param string $prefix An XML prefix e.g. "imsmd".
@throws InvalidArgumentException If $prefix is not a string or an empty string.
Set the XML prefix of the mapping .