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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 SetEnvironmentVariable(self, name, value):
 """Sets an environment variable in the Windows path helper. Args: name (str):
 name of the environment variable without enclosing %-characters, e.g. SystemRoot as in %SystemRoot%. value (str):
 value of the environment variable. """

    if isinstance(value, py2to3.STRING_TYPES):
      value = self._PathStripPrefix(value)

    if value is not None:
      self._environment_variables[name.upper()] = value