public function get_mapping_attribute( $metakey ) {
		$mapping = array_flip( $this->get_mapping() );

		return isset( $mapping[ $metakey ] ) ? $mapping[ $metakey ] : null;
	}
public function get_mapping_attribute( $metakey ) {
		$mapping = array_flip( $this->get_mapping() );

		return isset( $mapping[ $metakey ] ) ? $mapping[ $metakey ] : null;
	}
public function get_mapping_attribute ( $ metakey ) { $ mapping = array_flip ( $ this -> get_mapping ( ) ) ; return isset ( $ mapping [ $ metakey ] ) ? $ mapping [ $ metakey ] : null ; }
Get the mapping attribute by special metakey.

@param  string $metakey The metakey key to get attribute.
@return string|null
Get the mapping attribute by special metakey .