code: private static MappedField checkAccessors(XML xml, Class<?> aClass, Field nestedField){
  
  		MappedField field = checkGetAccessor(xml, aClass, nestedField);
  		verifySetterMethods(aClass,field);
  		return field;
  	}
docs: Checks get and set accessors of this field.
  @param xml used to check xml configuration
  @param aClass class where is the field with the nested mapping
  @param nestedField field with nested mapping
  @return mapped field