shadows/framework/src/main/java/org/robolectric/shadows/ShadowStatFs.java
public static void registerStats(String path, int blockCount, int freeBlocks,
      int availableBlocks) {
    stats.put(path, new Stats(blockCount, freeBlocks, availableBlocks));
  }
public static void registerStats(String path, int blockCount, int freeBlocks,
      int availableBlocks) {
    stats.put(path, new Stats(blockCount, freeBlocks, availableBlocks));
  }
Register stats for a path, which will be used when a matching {@link StatFs} instance is
created.  A {@link StatFs} instance matches if it extends path. If several registered paths
match, we pick the longest one.

@param path path to the file
@param blockCount number of blocks
@param freeBlocks number of free blocks
@param availableBlocks number of available blocks