old_contents: 'use strict';
  
  var Node = require('../node');
  var dot = require('dot');
  
  var TYPE = 'weighted-centroid';
  
  var PARAMS = {
      source : Node.PARAM.NODE(Node.GEOMETRY.POINT),
      weight_column : Node.PARAM.STRING,
      category_column : Node.PARAM.STRING
  };
  
  var WeightedCentroid  = Node.create(TYPE, PARAMS, {cache: true});
  
  module.exports = WeightedCentroid;
  module.exports.TYPE = TYPE;
  module.exports.PARAMS = PARAMS;
  
  var weightedCentroidTemplate = dot.template([
      'SELECT the_geom , class',
      'FROM cdb_crankshaft.CDB_WeightedMean(\'{{=it.query}}\',\'{{=it.weight_column}}\',\'{{=it.category_column}}\')'
  ].join('\n'));
  
  function query(it) {
      return weightedCentroidTemplate(it);
  }
  
  WeightedCentroid.prototype.sql = function(){
      return query({
          query : this.source.getQuery(),
          weight_column : this.weight_column,
          category_column : this.category_column
      });
  };
          
  
new_contents: 'use strict';
  
  var Node = require('../node');
  var dot = require('dot');
  
  var TYPE = 'weighted-centroid';
  
  var PARAMS = {
      source : Node.PARAM.NODE(Node.GEOMETRY.POINT),
      weight_column : Node.PARAM.STRING,
      category_column : Node.PARAM.STRING
  };
  
  var WeightedCentroid  = Node.create(TYPE, PARAMS, {cache: true});
  
  module.exports = WeightedCentroid;
  module.exports.TYPE = TYPE;
  module.exports.PARAMS = PARAMS;
  
  var weightedCentroidTemplate = dot.template([
      'SELECT the_geom , class',
      'FROM cdb_crankshaft.CDB_WeightedMean($weightedmean_query${{=it.query}}$weightedmean_query$,\'{{=it.weight_column}}\',\'{{=it.category_column}}\')'
  ].join('\n'));
  
  function query(it) {
      return weightedCentroidTemplate(it);
  }
  
  WeightedCentroid.prototype.sql = function(){
      return query({
          query : this.source.getQuery(),
          weight_column : this.weight_column,
          category_column : this.category_column
      });
  };
          
  
subject: Use $$ for escaping