question: public Edge findEdge ( Coordinate p0 , Coordinate p1 ) { for ( int i = 0 ; i < edges . size ( ) ; i ++ ) { Edge e = ( Edge ) edges . get ( i ) ; Coordinate [ ] eCoord = e . getCoordinates ( ) ; if ( p0 . equals ( eCoord [ 0 ] ) && p1 . equals ( eCoord [ 1 ] ) ) return e ; } return null ; }
target:  Returns the edge whose first two coordinates are p0 and p1