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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 read_credentials(self, credentials):
 """ Reads credentials from configuration parameters. Each section represents an individual CredentialParams :param credentials: configuration parameters to be read """

        self._items.clear()
        for key in credentials.get_key_names():
            value = credentials.get_as_nullable_string(key)
            self._items.append(CredentialParams.from_tuples([key, value]))