public ExtentFields(Field xMinField, Field yMinField, Field xMaxField, Field yMaxField)
 {
     XMinField = xMinField;
     XMaxField = xMaxField;
     YMinField = yMinField;
     YMaxField = yMaxField;
 }
 // Retrieves the specified field from the current locator service's candidate fields
 private Field findCandidateField(Field field)
 {
     return LocatorInfo.CandidateFields.FirstOrDefault(f => f.Name == field.Name);
 }