Issue with classes in sets

[claygorman]

Hello,

I love this library but I have ran into an issue I thought I could pick you brain on.

In the example https://pythonhosted.org/Flask-Principal/#granular-resource-protection i implemented almost identically to how it states there but I have an issue. When calling if permission.can(): I get False back from the following line... https://github.com/mattupstate/flask-principal/blob/master/flask_principal.py#L333-L334

In order to make this work I had to implement the following.

class EditBlogPostPermission(Permission):
    def __init__(self, post_id):
        need = EditBlogPostNeed(unicode(post_id))
        super(EditBlogPostPermission, self).__init__(need)
        self.need = need

    def __eq__(self, other):
        """Override the default Equals behavior."""
        if isinstance(other, self.need.__class__):
            return self.need == other
        return False

    def __ne__(self, other):
        """Override the default Unequal behavior."""
        return self.need != other

    def __hash__(self):
        """Override the default Hash behavior."""
        return hash(self.need)

Do you have any suggestions on how to better implement this? I dont see any tests in your test file for this use case.

I also considered the following instead of the __eq__, __ne__, __hash__

    def allows(self, identity):
        for prov in identity.provides:
            if isinstance(self, type(prov)) and self.needs == prov.needs:
                return True
         
        return False