public function setConstraint(\Closure $callback)
    {
        $this->items = [];
        $this->loaded = FALSE;
        $this->queryConstraint = $callback;
    }
public function setConstraint(\Closure $callback)
    {
        $this->items = [];
        $this->loaded = FALSE;
        $this->queryConstraint = $callback;
    }
public function setConstraint ( \ Closure $ callback ) { $ this -> items = [ ] ; $ this -> loaded = FALSE ; $ this -> queryConstraint = $ callback ; }
Set the query constraint.

@param \Closure $callback
Set the query constraint .