code: public String getFromEnvOrSystemProperty(String propName) {
  
      String val = System.getenv(propName);
      if (val == null)
        val = System.getProperty(propName);
      return val;
    }
docs: Looks for the value of a given property in the environment or in the system
  properties
  
  @param propName
  the property that will be looked for
  @return the property value, or null if no property was found