def METHOD_NAME(self):
    """Test multiple includes, where both include the same base mod.
    The base mod should only be included once.
    """
    self.createUserMod("base")
    self.createUserMod("derived1", include_dirs=["base"])
    self.createUserMod("derived2", include_dirs=["base"])
    self.createUserMod("derived_combo", include_dirs=["derived1", "derived2"])
    apply_user_mods(
        self._caseroot, os.path.join(self._user_mods_parent_dir, "derived_combo")
    )
    # NOTE(wjs, 2017-04-15) The ordering of derived1 vs. derived2 is not
    # critical here: If this aspect of the behavior changes, the
    # expected_contents can be changed to match the new behavior in this
    # respect.
    expected_contents = """base