find_with_equal_func
Description:
[ Version ( since = "2.64" ) ]
public bool find_with_equal_func (Object? item, EqualFunc<Object> equal_func, out uint position)
  public bool find_with_equal_func (Object? item, EqualFunc<Object> equal_func, out uint position)
Looks up the given item in the list store by looping over the items and comparing them with equal_func until the 
      first occurrence of item which matches.
 If item was not found, then position will not be set, and this method will return false
      .
item is always passed as second parameter to equal_func.
Since GLib 2.76 it is possible to pass `NULL` for item.
Parameters:
| this | |
| item | 
           an item  | 
      
| equal_func | 
           A custom equality check function  | 
      
| position | 
           the first position of   | 
      
Returns:
| 
           Whether this contains   |