def has_constant(self, constant):
return constant in self.constants<EOL>
Check if the current ``Choices`` object has the given constant.

        Parameters
        ----------
        constant: string
            Name of the constant we want to check..

        Returns
        -------
        boolean
            ``True`` if the constant is present, ``False`` otherwise.

        Example
        -------

        >>> MY_CHOICES = Choices(('FOO', 1, 'foo'), ('BAR', 2, 'bar'))
        >>> MY_CHOICES.has_constant('FOO')
        True
        >>> MY_CHOICES.has_constant('QUX')
        False