code: def _toMathInfo(self, guidelines=True):
          
          import fontMath
          # A little trickery is needed here because MathInfo
          # handles font level guidelines. Those are not in this
          # object so we temporarily fake them just enough for
          # MathInfo and then move them back to the proper place.
          self.guidelines = []
          if guidelines:
              for guideline in self.font.guidelines:
                  d = dict(
                      x=guideline.x,
                      y=guideline.y,
                      angle=guideline.angle,
                      name=guideline.name,
                      identifier=guideline.identifier,
                      color=guideline.color
                  )
                  self.guidelines.append(d)
          info = fontMath.MathInfo(self)
          del self.guidelines
          return info
docs: Subclasses may override this method.