def eval(self, code, **vars):
        """Evaluate 'code' in the frame.

        'vars' are optional additional local variables.

        Returns the result of the evaluation.
        """
        f_locals = self.f_locals.copy()
        f_locals.update(vars)
        return eval(code, self.f_globals, f_locals)
Evaluate 'code' in the frame.

        'vars' are optional additional local variables.

        Returns the result of the evaluation.
        
src/_pytest/_code/code.py