docs: function(sources){
        if (!sources)
          sources = {};
  
        for (var name in this.fields.sources)
          this.setSource(name, sources[name]);
  
        /** @cut */ for (var name in sources)
        /** @cut */   if (name in this.fields.sources == false)
        /** @cut */     basis.dev.warn('basis.data.object.Merge#setSource: can\'t set source with name `' + name + '` as not specified by fields configuration');
      }