code: def add_variable(self, key, value, system_wide=False):
          
          if system_wide:
              javabridge.call(self.jobject, "addVariableSystemWide", "(Ljava/lang/String;Ljava/lang/String;)V", key, value)
          else:
              javabridge.call(self.jobject, "addVariable", "(Ljava/lang/String;Ljava/lang/String;)V", key, value)
docs: Adds the environment variable.
  
          :param key: the name of the variable
          :type key: str
          :param value: the value
          :type value: str
          :param system_wide: whether to add the variable system wide
          :type system_wide: bool