22465: [CEA] sometimes isinstance(m, Mesh) returns False for Mesh objects // PPGP pb

22465: [CEA] sometimes isinstance(m, Mesh) returns False for Mesh objects // PPGP pb

class MeshMeta(type):
    def __instancecheck__(cls, inst):
        """Implement isinstance(inst, cls)."""
        return any(cls.__subclasscheck__(c)
                   for c in {type(inst), inst.__class__})

    def __subclasscheck__(cls, sub):
        """Implement issubclass(sub, cls)."""
        return type.__subclasscheck__(cls, sub) or (cls.__name__ == sub.__name__ and cls.__module__ == sub.__module__)

...

class Mesh:
    __metaclass__ = MeshMeta

...