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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def get_value(self, obj, attr, accessor=None, default=missing_):
 """Return the value for a given key from an object. :param object obj: The object to get the value from :param str attr: The attribute/key in `obj` to get the value from. :param callable accessor: A callable used to retrieve the value of `attr` from the object `obj`. Defaults to `marshmallow.utils.get_value`. """

        # NOTE: Use getattr instead of direct attribute access here so that
        # subclasses aren't required to define `attribute` member
        attribute = getattr(self, 'attribute', None)
        accessor_func = accessor or utils.get_value
        check_key = attr if attribute is None else attribute
        return accessor_func(obj, check_key, default)