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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 flush(self):
 """ Commit cached writes to the file handle. Does not flush libc buffers or notifies the kernel, so these changes may not immediately be visible to other processes. Updates the fingerprints whena writes happen, so successive ``flush()`` invocations are no-ops. It is not necessary to call this method in user code. Notes ----- .. versionadded:: 1.6 This method is not intended as user-oriented functionality, but might be useful in certain contexts to provide stronger guarantees. """

        garbage = []
        for i, (x, signature) in self.refs.items():
            if sys.getrefcount(x) == 3:
                garbage.append(i)

            if fingerprint(x) == signature: continue

            self.filehandle.puttr(i, x)
            signature = fingerprint(x)


        # to avoid too many resource leaks, when this dict is the only one
        # holding references to already-produced traces, clear them
        for i in garbage:
            del self.refs[i]