code: public synchronized int read(int blockOffset, byte[] buffer, int offset, int length) 
  			throws IOException {
  		return provider.read(blockNumber, blockOffset, buffer, offset, length);
  	}
docs: Read a number of bytes from this block.
  
  @param blockOffset Offset, in bytes, within this block.
  @param buffer Buffer to store read data in.
  @param offset Offset within the buffer to write to.
  @param length Number of bytes to be read.
  @return The number of read bytes.