question: public final boolean shares_layer ( BrdItem p_other ) { int max_first_layer = Math . max ( first_layer ( ) , p_other . first_layer ( ) ) ; int min_last_layer = Math . min ( last_layer ( ) , p_other . last_layer ( ) ) ; return max_first_layer <= min_last_layer ; }
target:  Returns true, if some shapes of this item and p_other are on the same layer.