'Merges to EnvironmentVariables instances.
Args:
env_variables_one: The first EnvironmentVariables instance or None.
env_variables_two: The second EnvironmentVariables instance or None.
Returns:
The merged EnvironmentVariables instance, or None if both input instances
are None or empty.
If a variable is specified by both instances, the value from
env_variables_two is used.'

@classmethod
def Merge(cls, env_variables_one, env_variables_two):

    result_env_variables = (env_variables_one or {}).copy()
    result_env_variables.update((env_variables_two or {}))
    return (EnvironmentVariables(**result_env_variables) if result_env_variables else None)
