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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def com_daltonmaag_check_recommended_fields(ufo_font):
 """Check that recommended fields are present in the UFO fontinfo. This includes fields that should be in any production font. """

  recommended_fields = []

  for field in [
      "postscriptUnderlineThickness", "postscriptUnderlinePosition",
      "versionMajor", "versionMinor", "styleName", "copyright",
      "openTypeOS2Panose"
  ]:
    if ufo_font.info.__dict__.get("_" + field) is None:
      recommended_fields.append(field)

  if recommended_fields:
    yield WARN, f"Recommended field(s) missing: {recommended_fields}"
  else:
    yield PASS, "Recommended fields present."