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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 _execute_pip(self, args, log=True):
 """ Executes pip commands. :param args: Arguments to pass to pip (list[str]) :param log: Log the output to a file [default: True] (boolean) :return: See _execute """


        # Copy the pip calling arguments so they can be extended
        exec_args = list(self._pip)

        # Older versions of pip don't support the version check argument.
        # Fixes https://github.com/sjkingo/virtualenv-api/issues/35
        if self.pip_version[0] >= 6:
            exec_args.append('--disable-pip-version-check')

        exec_args.extend(args)
        return self._execute(exec_args, log=log)