.. function:: create_string_buffer(init, size=None)              create_string_buffer(size)   Create a mutable character buffer. The returned object is a   ctypes array of :class:`c_char`.   If *size* is given (and not None), it must be an :cls:`int.   It specifies the size of the returned array.   If the *init* argument is given, it must be :cls:`bytes`. It is used   to initialize the array items. Bytes not initialized this way are   set to zero (NUL).   If *size* is not given (or if it is None), the buffer is made one byte   larger than *init*, effectively adding a NUL termination byte.   If both arguments are given, *size* must not be less than ``len(init)``.   .. warning::      If *size* is equal to ``len(init)``, a NUL terminator is      not added. Do not treat such a buffer as a C string.   For example::      >>> bytes(create_string_buffer(2))      b'\x00\x00'      >>> bytes(create_string_buffer(b'ab'))      b'ab\x00'      >>> bytes(create_string_buffer(b'ab', 2))      b'ab'      >>> bytes(create_string_buffer(b'ab', 4))      b'ab\x00\x00'      >>> bytes(create_string_buffer(b'abcdef', 2))      Traceback (most recent call last):         ...      ValueError: byte string too long