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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 run(self, block=True, binary=False, cwd=None):
 """Runs the given command, with or without pexpect functionality enabled."""

        self.blocking = block

        # Use subprocess.
        if self.blocking:
            popen_kwargs = self._default_popen_kwargs.copy()
            popen_kwargs['universal_newlines'] = not binary
            if cwd:
                popen_kwargs['cwd'] = cwd
            s = subprocess.Popen(self._popen_args, **popen_kwargs)
        # Otherwise, use pexpect.
        else:
            pexpect_kwargs = self._default_pexpect_kwargs.copy()
            if binary:
                pexpect_kwargs['encoding'] = None
            if cwd:
                pexpect_kwargs['cwd'] = cwd
            # Enable Python subprocesses to work with expect functionality.
            pexpect_kwargs['env']['PYTHONUNBUFFERED'] = '1'
            s = PopenSpawn(self._popen_args, **pexpect_kwargs)
        self.subprocess = s
        self.was_run = True