question: public void testCorrectBuild ( ) { Iterator < String > iter = m_Trie . iterator ( ) ; HashSet < String > set = new HashSet < String > ( ) ; while ( iter . hasNext ( ) ) set . add ( iter . next ( ) ) ; assertEquals ( "size() does not reflect number of added strings" , m_Data . length , m_Trie . size ( ) ) ; assertEquals ( "Iterator returns different number of strings" , m_Data . length , set . size ( ) ) ; for ( int i = 0 ; i < m_Data . length ; i ++ ) { if ( ! set . contains ( m_Data [ i ] ) ) fail ( "Cannot find string '" + m_Data [ i ] + "'" ) ; } }
target:  tests whether all the string the Trie got built with can be retrieved again (tests building and retrieval via iterator).