<s>[INST] makes sure the passed object is in the collection . equals comparison . concode_field_sep int _size concode_elem_sep List4 _last concode_elem_sep List4 _first concode_elem_sep int _version concode_field_sep void prepend concode_elem_sep void replace concode_elem_sep boolean remove concode_elem_sep Object singleElement concode_elem_sep Iterator4 iterator concode_elem_sep void removeAll concode_elem_sep void removeAll concode_elem_sep List4 find concode_elem_sep void assertNotNull concode_elem_sep Object get concode_elem_sep Object get concode_elem_sep void replaceByIdentity concode_elem_sep Object[] toArray concode_elem_sep Object[] toArray concode_elem_sep void adjustOnRemoval concode_elem_sep int indexOf concode_elem_sep void doPrepend concode_elem_sep List4 findByIdentity concode_elem_sep boolean add concode_elem_sep void doAdd concode_elem_sep boolean containsAll concode_elem_sep void clear concode_elem_sep boolean isEmpty concode_elem_sep int version concode_elem_sep boolean contains concode_elem_sep int size concode_elem_sep void addAll concode_elem_sep void addAll concode_elem_sep void addAll concode_elem_sep Object deepClone concode_elem_sep boolean containsByIdentity concode_elem_sep String toString concode_elem_sep Iterator4 internalIterator concode_elem_sep void changed [/INST] Object function ( Object arg0 ) { List4 loc0 = find ( arg0 ) ; if ( loc0 == null ) { add ( arg0 ) ; return arg0 ; } return loc0 . _element ; </s>