code: function PostcssCompiler(inputTrees, inputFile, outputFile, plugins, map, useSass, includePaths) {
  	if (!(this instanceof PostcssCompiler)) {
  		return new PostcssCompiler(inputTrees, inputFile, outputFile, plugins, map);
  	}
  
  	if (!Array.isArray(inputTrees)) {
  		throw new Error('Expected array for first argument - did you mean [tree] instead of tree?');
  	}
  
  	CachingWriter.call(this, inputTrees, inputFile);
  
  	this.inputFile = inputFile;
  	this.outputFile = outputFile;
  	this.plugins = plugins || [];
  	this.map = map || {};
  	this.warningStream = process.stderr;
      this.useSass = useSass || false;
  	this.includePaths = includePaths || [];
  }
docs: rip of broccoli-postcss