code: func SetFormat(formatSpec string) logging.Formatter {
  	if formatSpec == "" {
  		formatSpec = defaultFormat
  	}
  	return logging.MustStringFormatter(formatSpec)
  }
docs: // These interfaces are used by the chaincode shim at the 1.2 version.
  // If we remove them, vendored shims are unlikely to compile against
  // newer levels of the peer.
  // SetFormat(string) logging.Formatter
  // InitBackend(logging.Formatter, io.Writer)
  // DefaultLevel() string
  // InitFromSpec(string) string
  // SetFormat sets the logging format.