Class to create env var in Java

Environment

import com.google.common.annotations.VisibleForTesting;

import java.lang.reflect.Field;
import java.util.Map;

@VisibleForTesting
public class Environment {
  public static void set(String key, String value) {
    try {
      Map<String, String> env = System.getenv();
      Class<?> cl = env.getClass();
      Field field = cl.getDeclaredField("m");
      field.setAccessible(true);
      Map<String, String> writableEnv = (Map<String, String>) field.get(env);
      writableEnv.put(key, value);
    } catch (Exception e) {
      throw new IllegalStateException("Failed to set environment variable", e);
    }
  }
}