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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def invalid_fields(self, data, original_data):
 """Validator that checks if any keys provided aren't in the schema. Say your schema has support for keys ``a`` and ``b`` and the data provided has keys ``a``, ``b``, and ``c``. When the data is loaded into the schema, a :class:`marshmallow.ValidationError` will be raised informing the developer that excess keys have been provided. Raises: marshmallow.ValidationError: Raised if extra keys exist in the passed in data. """

        errors = []

        for field in original_data:
            # Skip nested fields because they will loop infinitely
            if isinstance(field, (set, list, tuple, dict)):
                continue

            if field not in self.fields.keys():
                errors.append(field)

        if errors:
            raise ValidationError("Invalid field", field_names=errors)