see signatur oper check match oper list paramet type order paramet signific version check paramet kind op op appear signatur purist probabl suggest kind match exactli differenti paramet unlik practic oo languag abl distinguish instanti inout paramet ignor paramet complet line java regard code code code code have signatur need modifi method care numer telegraph pole problem involv work pair mix list param op oper signatur compar param op second oper signatur compar code code signatur match code code signatur match object op object op check name match model facad op model facad op equal check paramet list match iter param model facad paramet op iter iter param model facad paramet op iter param param non paramet non left object param param model facad object param param model facad list length differ length compar type paramet type match object type model facad type type object type model facad type type type equal type pair param let check pair param param list length 