docs: def getClosestZoom(self, resolution, unit='meters'):
          """
          Return the closest zoom level for a given resolution
          Parameters:
              resolution -- max. resolution
              unit -- unit for output (default='meters')
          """
          lo, hi = self._getZoomLevelRange(resolution, unit)
          if lo == 0:
              return lo
          if hi == len(self.RESOLUTIONS):
              return hi - 1
          before = self.RESOLUTIONS[lo - 1]
          if abs(self.RESOLUTIONS[lo] - resolution) < abs(before - resolution):
              return lo
          return lo - 1