question: protected Map < BindingSetHashKey , List < BindingSet > > makeHashTable ( int initialSize ) { Map < BindingSetHashKey , List < BindingSet > > nextHashTable ; if ( joinAttributes . length > 0 ) { nextHashTable = new HashMap < BindingSetHashKey , List < BindingSet > > ( initialSize ) ; } else { List < BindingSet > l = ( initialSize > 0 ) ? new ArrayList < BindingSet > ( initialSize ) : null ; nextHashTable = Collections . < BindingSetHashKey , List < BindingSet > > singletonMap ( BindingSetHashKey . EMPTY , l ) ; } return nextHashTable ; }
target:  Utility methods to make it easier to inserted custom store dependent maps