@classmethod
def _eager_b(cls, eager):
    """
        Builds the provided list of eager values, preparing them
        according to the current model rules.

        The composition process includes the extension of the provided
        sequence of eager values with the base ones defined in the
        model, if not handled correctly this is an expensive operation.

        :type eager: List/Tuple
        :param eager: The base sequence containing the various fields
        that should be eagerly loaded for the operation.
        :rtype: Tuple
        :return: The "final" resolved tuple that may be used for the eager
        loaded operation performance.
        """
    eager = list(eager) if eager else []
    eagers = cls.eagers()
    eager.extend(eagers)
    if not eager:
        return eager
    eager = tuple(set(eager))
    return eager
