question: forget the current environment and return the previously pushed state . concode_field_sep ArrayList<Node[]> trail concode_elem_sep int index concode_elem_sep Node[] environment concode_field_sep Node getGroundVersion concode_elem_sep boolean bind concode_elem_sep boolean bind concode_elem_sep void bindNoCheck concode_elem_sep Node getBinding concode_elem_sep void commit concode_elem_sep void reset concode_elem_sep Node[] getEnvironment concode_elem_sep Triple instantiate concode_elem_sep void push
target: void function ( ) { if ( index > 0 ) { environment = trail . get ( -- index ) ; trail . set ( index , null ) ; } else { throw new IndexOutOfBoundsException ( "srini_string" ) ; } }