code: function _map_to_try(doc_key, map_field, item_key){
  
  		    var retlbl = null;
  
  		    var map_str = anchor.get_doc_field(doc_key, map_field);
  
  		    if( map_str && bbop.core.what_is(map_str) == 'string' ){
  
  			// First, check the cache. If it's not there
  			// add it.
  			if( ! bbop.core.is_defined(anchor._doc_label_maps[doc_key]) ){
  			    anchor._doc_label_maps[doc_key] = {};
  			}
  			if( ! bbop.core.is_defined(anchor._doc_label_maps[doc_key][map_field]) ){
  			    // It looks like a map wasn't defined, so let's
  			    // convert it into JSON now.
  			    anchor._doc_label_maps[doc_key][map_field] =
  				bbop.json.parse(map_str);
  			}
  
  			// Pull our map out of the cache.
  			var map = anchor._doc_label_maps[doc_key][map_field];
  
  			// Probe to see if we have anything in the map.
  			if( map && map[item_key] ){
  			    retlbl = map[item_key];
  			}
  		    }
  
  		    return retlbl;
  		}
docs: Since we'll do this twice with different map fields, a generic function to try and probe a JSON string map (caching it along the way) for a label.