class_docstr: Filter field skip log messges.
  
  At most, one message per field skipped per loop will be passed.
docstr: Pass record if not seen.
code: def filter(self, record):
      """Pass record if not seen."""
      msg = record.getMessage()
      if msg.startswith("Skipping field"):
          retval = msg not in self.seen_msgs
          self.seen_msgs.add(msg)
          return retval
      else:
          return 1
  
file_path: Fiona/fiona/logutils.py
imports: import logging
label_desc: Use image node_id 2 for calling the FieldSkipLogFilter obj's underlying member method code with example usage: obj.filter(record) and returns: retval, int