'Verify name has a True or False value.
Args:
name [string]: variable name.'

def verify_true_false(self, name):

    value = self.__bindings.get(name)
    if self.is_reference(value):
        self.__errors.append('Missing    "{name}".'.format(name=name))
        return False
    if isinstance(value, bool):
        return True
    self.__errors.append('{name}={value!r}    is    not    valid.    Must    be    boolean    true    or    false.'.format(name=name, value=value))
    return False
