returns the previous state . if the size of the stack is 0 , an exception is thrown . if the size is 1 , an empty node is returned . concode_field_sep T data concode_elem_sep int size concode_elem_sep TreeShapedStack<T> previous concode_field_sep int size concode_elem_sep int hashCode concode_elem_sep boolean equals concode_elem_sep String internalToString concode_elem_sep String toString concode_elem_sep String toString concode_elem_sep TreeShapedStack<T> push concode_elem_sep List<T> asList concode_elem_sep T peek
TreeShapedStack < T > function ( ) { if ( size == 0 ) { throw new EmptyStackException ( ) ; } return previous ; }