code: def interpolate_layout(
      designspace, loc, master_finder=lambda s: s, mapped=False
  ):
      """
      Interpolate GPOS from a designspace file and location.
  
      If master_finder is set, it should be a callable that takes master
      filename as found in designspace file and map it to master font
      binary as to be opened (eg. .ttf or .otf).
  
      If mapped is False (default), then location is mapped using the
      map element of the axes in designspace file.  If mapped is True,
      it is assumed that location is in designspace's internal space and
      no mapping is performed.
      """
      if hasattr(
          designspace, "sources"
      ):  # Assume a DesignspaceDocument
          pass
      else:  # Assume a file path
          from fontTools.designspaceLib import DesignSpaceDocument
  
          designspace = DesignSpaceDocument.fromfile(designspace)
  
      ds = load_designspace(designspace)
      log.info("Building interpolated font")
  
      log.info("Loading master fonts")
      master_fonts = load_masters(designspace, master_finder)
      font = deepcopy(master_fonts[ds.base_idx])
  
      log.info("Location: %s", pformat(loc))
      if not mapped:
          loc = {
              name: ds.axes[name].map_forward(v)
              for name, v in loc.items()
          }
      log.info("Internal location: %s", pformat(loc))
      loc = models.normalizeLocation(loc, ds.internal_axis_supports)
      log.info("Normalized location: %s", pformat(loc))
  
      # Assume single-model for now.
      model = models.VariationModel(ds.normalized_master_locs)
      assert 0 == model.mapping[ds.base_idx]
  
      merger = InstancerMerger(font, model, loc)
  
      log.info("Building interpolated tables")
      # TODO GSUB/GDEF
      merger.mergeTables(font, master_fonts, ["GPOS"])
      return font
  
file_path: catboost/contrib/python/fonttools/fontTools/varLib/interpolate_layout.py
imports: from fontTools.ttLib import TTFont
  from fontTools.varLib import models, VarLibError, load_designspace, load_masters
  from fontTools.varLib.merger import InstancerMerger
  import os.path
  import logging
  from copy import deepcopy
  from pprint import pformat
label_desc: Use image node_id 1 for calling a global function with example usage: interpolate_layout(designspace, loc, master_finder, mapped) and returns: font