def METHOD_NAME(self):
    env = robjects.Environment()
    env['a.a'] = robjects.StrVector('abcd')
    env['b'] = robjects.IntVector((1,2,3))
    env['c'] = robjects.r(''' function(x) x^2''')
    pck = robjects.packages.Package(env, "dummy_package")
    assert isinstance(pck.a_a, robjects.Vector)
    assert isinstance(pck.b, robjects.Vector)
    assert isinstance(pck.c, robjects.Function)