question: public void acquireProbabilities ( final String string ) { if ( string . length ( ) < 2 ) { return ; } for ( int i = 2 ; i < string . length ( ) ; ++ i ) { final char previousChar = string . charAt ( i - 2 ) ; final char currentChar = string . charAt ( i - 1 ) ; final char nextChar = string . charAt ( i ) ; final String key = previousChar + "" + currentChar ; if ( ! sequences . contains ( key ) ) { sequences . add ( key ) ; } HashMap < Character , Integer > probabilities = sequenceProbabilities . get ( key ) ; if ( probabilities == null ) { probabilities = new HashMap < > ( ) ; sequenceProbabilities . put ( key , probabilities ) ; } int existingValue = probabilities . getOrDefault ( nextChar , 0 ) ; ++ existingValue ; probabilities . put ( nextChar , existingValue ) ; } }
target:  Parses the specified String to determine the probability of a character appearing after the previous two characters beginning with the third character in the String and ending with the last.