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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 iter_fields(self, schema: Schema) -> Iterable[Tuple[str, Field]]: """ Iterate through marshmallow schema fields. Generates: name, field pairs """

        for name in sorted(schema.fields.keys()):
            field = schema.fields[name]
            yield field.dump_to or name, field