code: public static Set<Field> getInstanceFields(Class<?> clazz, Filter<Field> filter) {
  		return getFields(clazz, 
  				new And<Field>(
  					filter != null ? filter : new True<Field>(), 
  					new Not<Field>(
  						new IsStatic<Field>()
  					), 
  					new Not<Field>(
  						new IsOverridden<Field>()
  					)
  				)
  			);
  	}
docs: Returns the filtered set of instance fields of the given class, including
  those inherited from the super-classes.
  
  @param clazz
  the class whose fields are being retrieved.
  @param filter
  an optional filter; to get all fields pass in a {@code null} value.
  @return
  the filtered set of fields from the given class and its super-classes.