def METHOD_NAME():
    assert is_valid_email("a@b.cc")
    assert is_valid_email("te.st+email.valid@a.org.au.xx.yy")
    assert is_valid_email("invalid@yahoo.co.uk")
    assert not is_valid_email("invalid@.yahoo.co.uk")
    assert not is_valid_email("test email@couchers.org")
    assert not is_valid_email(".testemail@couchers.org")
    assert not is_valid_email("testemail@couchersorg")
    assert not is_valid_email("b@xxb....blabla")