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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 GetContract(self, script_hash):
 """ Get contract for specified script_hash. Args: script_hash (UInt160):
 a bytearray (len 20). Returns: Contract: if a contract was found matching the provided script hash, otherwise None """

        if script_hash.ToBytes() in self._contracts.keys():
            return self._contracts[script_hash.ToBytes()]
        return None