private RegularFile createFile() {
    return RegularFile.create(-1, fileTimeSource.now(), new HeapDisk(BLOCK_SIZE, 2, 2));
  }
Tests for the lower-level operations dealing with the blocks of a {@link RegularFile}.

@author Colin Decker
jimfs/src/test/java/com/google/common/jimfs/RegularFileBlocksTest.java