private int getChunkId(String chromosome, int chunk64k) {
        int chunkId, pos = chunk64k * chunkSize64k + 1;
        String key = buildChunkMapKey(chromosome, pos);
        if (chunkIdMap.containsKey(key)) {
            chunkId = chunkIdMap.get(key);
        } else {
            throw new InternalError("Coverage chunk " + chromosome
                    + ":" + pos + "-, not found in database (64-chunk : " + chunk64k + ")");
        }
        return chunkId;
    }
private int getChunkId ( String chromosome , int chunk64k ) { int chunkId , pos = chunk64k * chunkSize64k + 1 ; String key = buildChunkMapKey ( chromosome , pos ) ; if ( chunkIdMap . containsKey ( key ) ) { chunkId = chunkIdMap . get ( key ) ; } else { throw new InternalError ( "Coverage chunk " + chromosome + ":" + pos + "-, not found in database (64-chunk : " + chunk64k + ")" ) ; } return chunkId ; }
Get the chunk ID from the map of chunks.

@param chromosome    Chromosome of the chunk target
@param chunk64k         Number of 64k chunk
@return              Chunk ID in the database