code: function toSQL(method) {
      method = method || this.method;
      var val = this[method]();
      var defaults = {
        method: method,
        options: assign({}, this.options),
        bindings: this.formatter.bindings
      };
      if (typeof val === 'string') {
        val = { sql: val };
      }
  
      if (method === 'select' && this.single.as) {
        defaults.as = this.single.as;
      }
      var out = assign(defaults, val);
      debug(out);
      return out;
    }
docs: Collapse the builder into a single object