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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 complete_nonnull_value( exe_context, # type: ExecutionContext return_type, # type: GraphQLNonNull field_asts, # type: List[Field] info, # type: ResolveInfo path, # type: List[Union[int, str]] result, # type: Any ):
 """ Complete a NonNull value by completing the inner type """

    completed = complete_value(
        exe_context, return_type.of_type, field_asts, info, path, result
    )
    if completed is None:
        raise GraphQLError(
            "Cannot return null for non-nullable field {}.{}.".format(
                info.parent_type, info.field_name
            ),
            field_asts,
            path=path,
        )

    return completed