public function eq($expression1, $expression2) : self
    {
        $this->expr->eq($expression1, $expression2);

        return $this;
    }
public function eq($expression1, $expression2) : self
    {
        $this->expr->eq($expression1, $expression2);

        return $this;
    }
public function eq ( $ expression1 , $ expression2 ) : self { $ this -> expr -> eq ( $ expression1 , $ expression2 ) ; return $ this ; }
Compares two values and returns whether they are equivalent.

@see http://docs.mongodb.org/manual/reference/operator/aggregation/eq/
@see Expr::eq

@param mixed|Expr $expression1
@param mixed|Expr $expression2
Compares two values and returns whether they are equivalent .