code: public ProcessExecutor environment(String name, String value) {
      environment.put(name, value);
      return this;
    }
docs: Adds a single additional environment variable for the process being executed.
  
  @param name name of the environment variable added to the process being executed.
  @param value value of the environment variable added to the process being executed.
  @return This process executor.
  
  @since 1.7