code: public String setValue(String name, String value) {
          return values.put(name, value);
      }
docs: Sets the value of the field having the given name. Any existing value
  for that field is replaced.
  
  @param name
  The name of the field whose value should be assigned.
  
  @param value
  The value to assign to the field having the given name.
  
  @return
  The previous value of the field, or null if the value of the field
  was not previously defined.