original_string: public function bindingKey($key = null)
      {
          deprecationWarning(
              get_called_class() . '::bindingKey() is deprecated. ' .
              'Use setBindingKey()/getBindingKey() instead.'
          );
          if ($key !== null) {
              $this->setBindingKey($key);
          }
  
          return $this->getBindingKey();
      }
code: public function bindingKey($key = null)
      {
          deprecationWarning(
              get_called_class() . '::bindingKey() is deprecated. ' .
              'Use setBindingKey()/getBindingKey() instead.'
          );
          if ($key !== null) {
              $this->setBindingKey($key);
          }
  
          return $this->getBindingKey();
      }
code_tokens: public function bindingKey ( $ key = null ) { deprecationWarning ( get_called_class ( ) . '::bindingKey() is deprecated. ' . 'Use setBindingKey()/getBindingKey() instead.' ) ; if ( $ key !== null ) { $ this -> setBindingKey ( $ key ) ; } return $ this -> getBindingKey ( ) ; }
docstring: Sets the name of the field representing the binding field with the target table.
  When not manually specified the primary key of the owning side table is used.
  
  If no parameters are passed the current field is returned
  
  @deprecated 3.4.0 Use setBindingKey()/getBindingKey() instead.
  @param string|null $key the table field to be used to link both tables together
  @return string|array
docstring_tokens: Sets the name of the field representing the binding field with the target table . When not manually specified the primary key of the owning side table is used .