question: public void alignTop ( ArrayList < Integer > nodes ) { if ( m_bNeedsUndoAction ) { addUndoAction ( new alignTopAction ( nodes ) ) ; } int nMinY = - 1 ; for ( int iNode = 0 ; iNode < nodes . size ( ) ; iNode ++ ) { int nY = getPositionY ( nodes . get ( iNode ) ) ; if ( nY < nMinY || iNode == 0 ) { nMinY = nY ; } } for ( int iNode = 0 ; iNode < nodes . size ( ) ; iNode ++ ) { int nNode = nodes . get ( iNode ) ; m_nPositionY . set ( nNode , nMinY ) ; } }
target:  align set of nodes with the top most node in the list