Add a large test for BinaryDictionary.addBigramWords().

import java.io.File;

import java.io.IOException;

import java.util.ArrayList;

import java.util.HashMap;

import java.util.Locale;

import java.util.Random;

        dictFile.delete();

    }

    public void testRandomlyAddBigramWords() {

        // TODO: Add a test to check the frequency of the bigram score which uses current value

        // calculated in the native code

        final int wordCount = 100;

        final int bigramCount = 1000;

        final int codePointSetSize = 50;

        final int seed = 11111;

        File dictFile = null;

        try {

            dictFile = createEmptyDictionaryAndGetFile("TestBinaryDictionary");

        } catch (IOException e) {

            fail("IOException while writing an initial dictionary : " + e);

        } catch (UnsupportedFormatException e) {

            fail("UnsupportedFormatException while writing an initial dictionary : " + e);

        }

        BinaryDictionary binaryDictionary = new BinaryDictionary(dictFile.getAbsolutePath(),

                0 /* offset */, dictFile.length(), true /* useFullEditDistance */,

                Locale.getDefault(), TEST_LOCALE, true /* isUpdatable */);

        final ArrayList<String> words = new ArrayList<String>();

        // Test a word that isn't contained within the dictionary.

        final Random random = new Random(seed);

        final int[] codePointSet = CodePointUtils.generateCodePointSet(codePointSetSize, random);

        final int unigramProbability = 100;

        final int bigramProbability = 10;

        for (int i = 0; i < wordCount; ++i) {

            final String word = CodePointUtils.generateWord(random, codePointSet);

            words.add(word);

            binaryDictionary.addUnigramWord(word, unigramProbability);

        }

        final boolean[][] bigramRelations = new boolean[wordCount][wordCount];

        for (int i = 0; i < bigramCount; i++) {

            final int word0Index = random.nextInt(wordCount);

            final int word1Index = random.nextInt(wordCount);

            final String word0 = words.get(word0Index);

            final String word1 = words.get(word1Index);

            bigramRelations[word0Index][word1Index] = true;

            binaryDictionary.addBigramWords(word0, word1, bigramProbability);

        }

        for (int i = 0; i < words.size(); i++) {

            for (int j = 0; j < words.size(); j++) {

                assertEquals(bigramRelations[i][j],

                        binaryDictionary.isValidBigram(words.get(i), words.get(j)));

            }

        }

        dictFile.delete();

    }

}