code: public static Optional<Object> getFieldValue(GenericRecord record, String fieldLocation) {
      Map<String, Object> ret = getMultiFieldValue(record, fieldLocation);
      return Optional.fromNullable(ret.get(fieldLocation));
    }
docs: Given a GenericRecord, this method will return the field specified by the path parameter. The fieldLocation
  parameter is an ordered string specifying the location of the nested field to retrieve. For example,
  field1.nestedField1 takes the the value of the field "field1", and retrieves the field "nestedField1" from it.
  @param record is the record to retrieve the field from
  @param fieldLocation is the location of the field
  @return the value of the field