class_docstr: Cache for file writers.
  
  This class caches file writers, one per directory.
docstr: Clear cached summary writers. Currently only used for unit tests.
docstr_tok: ["Clear","cached","summary","writers",".","Currently","only","used","for","unit","tests","."]
code: def clear():
      """Clear cached summary writers. Currently only used for unit tests."""
      with FileWriterCache._lock:
          # Make sure all the writers are closed now (otherwise open file handles
          # may hang around, blocking deletions on Windows).
          for item in FileWriterCache._cache.values():
              item.close()
          FileWriterCache._cache = {}
  
imports: import threading
  from tensorflow.python.framework import ops
  from tensorflow.python.summary.writer.writer import FileWriter
  from tensorflow.python.util.tf_export import tf_export
label_desc: Use image node_id 1 for calling the FileWriterCache obj's underlying member method code with example usage: obj.clear() without return types