docstr: See `setupHorizontalMetrics()` and `setupVerticalMetrics()`.
code: def setupMetrics(self, tableTag, metrics):
      """See `setupHorizontalMetrics()` and `setupVerticalMetrics()`."""
      assert tableTag in ("hmtx", "vmtx")
      mtxTable = self.font[tableTag] = newTable(tableTag)
      roundedMetrics = {}
      for gn in metrics:
          w, lsb = metrics[gn]
          roundedMetrics[gn] = int(round(w)), int(round(lsb))
      mtxTable.metrics = roundedMetrics
  
imports: from .ttLib import TTFont, newTable
  from .ttLib.tables._c_m_a_p import cmap_classes
  from .ttLib.tables._g_l_y_f import flagCubic
  from .ttLib.tables.O_S_2f_2 import Panose
  from .misc.timeTools import timestampNow
  import struct
  from collections import OrderedDict
label_desc: Use image node_id 21 for calling the FontBuilder obj's underlying member method code with example usage: obj.setupMetrics(tableTag, metrics) without return types