public function field(string $fieldName) : self
    {
        $fieldName          = $this->getDocumentPersister()->prepareFieldName($fieldName);
        $this->currentField = $fieldName;

        return $this;
    }
public function field(string $fieldName) : self
    {
        $fieldName          = $this->getDocumentPersister()->prepareFieldName($fieldName);
        $this->currentField = $fieldName;

        return $this;
    }
public function field ( string $ fieldName ) : self { $ fieldName = $ this -> getDocumentPersister ( ) -> prepareFieldName ( $ fieldName ) ; $ this -> currentField = $ fieldName ; return $ this ; }
Set the current field for building the expression.
Set the current field for building the expression .