Class numpy_like

testing/code/test_excinfo.py:1430–1436

    """

    class numpy_like:
        def __eq__(self, other):
            if type(other) is numpy_like:
                raise ValueError(
                    "The truth value of an array "
                    "with more than one element is ambiguous."
                )

    def a(x):
        return b(numpy_like())