def add_variable(self, key, value, system_wide=False):
        """
        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
        """
        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)
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