old_contents: import r from 'restructure';
  const fs = require('fs');
  
  var fontkit = {};
  export default fontkit;
  
  fontkit.logErrors = false;
  
  let formats = [];
  fontkit.registerFormat = function(format) {
    formats.push(format);
  };
  
  fontkit.openSync = function(filename, postscriptName) {
    if (BROWSER) {
      throw new Error('fontkit.openSync unavailable for browser build');
    }
    let buffer = fs.readFileSync(filename);
    return fontkit.create(buffer, postscriptName);
  };
  
  fontkit.open = function(filename, postscriptName, callback) {
    if (BROWSER) {
      throw new Error('fontkit.open unavailable for browser build');
    }
  
    if (typeof postscriptName === 'function') {
      callback = postscriptName;
      postscriptName = null;
    }
  
    fs.readFile(filename, function(err, buffer) {
      if (err) { return callback(err); }
  
      try {
        var font = fontkit.create(buffer, postscriptName);
      } catch (e) {
        return callback(e);
      }
  
      return callback(null, font);
    });
  
    return;
  };
  
  fontkit.create = function(buffer, postscriptName) {
    for (let i = 0; i < formats.length; i++) {
      let format = formats[i];
      if (format.probe(buffer)) {
        let font = new format(new r.DecodeStream(buffer));
        if (postscriptName) {
          return font.getFont(postscriptName);
        }
  
        return font;
      }
    }
  
    throw new Error('Unknown font format');
  };
  
  fontkit.defaultLanguage = 'en';
  fontkit.setDefaultLanguage = function(lang = 'en') {
    fontkit.defaultLanguage = lang;
  };
  
new_contents: import r from 'restructure';
  import fs from 'fs';
  
  var fontkit = {};
  export default fontkit;
  
  fontkit.logErrors = false;
  
  let formats = [];
  fontkit.registerFormat = function(format) {
    formats.push(format);
  };
  
  fontkit.openSync = function(filename, postscriptName) {
    if (BROWSER) {
      throw new Error('fontkit.openSync unavailable for browser build');
    }
    let buffer = fs.readFileSync(filename);
    return fontkit.create(buffer, postscriptName);
  };
  
  fontkit.open = function(filename, postscriptName, callback) {
    if (BROWSER) {
      throw new Error('fontkit.open unavailable for browser build');
    }
  
    if (typeof postscriptName === 'function') {
      callback = postscriptName;
      postscriptName = null;
    }
  
    fs.readFile(filename, function(err, buffer) {
      if (err) { return callback(err); }
  
      try {
        var font = fontkit.create(buffer, postscriptName);
      } catch (e) {
        return callback(e);
      }
  
      return callback(null, font);
    });
  
    return;
  };
  
  fontkit.create = function(buffer, postscriptName) {
    for (let i = 0; i < formats.length; i++) {
      let format = formats[i];
      if (format.probe(buffer)) {
        let font = new format(new r.DecodeStream(buffer));
        if (postscriptName) {
          return font.getFont(postscriptName);
        }
  
        return font;
      }
    }
  
    throw new Error('Unknown font format');
  };
  
  fontkit.defaultLanguage = 'en';
  fontkit.setDefaultLanguage = function(lang = 'en') {
    fontkit.defaultLanguage = lang;
  };
  
subject: Fix require fs in fontkit build