docs: public boolean canAcceptChild() {
          if (maxChildren == 0) {
              rejectReason = getDisplayName() + " does not accept any children.";
          } else if (getChildCount() >= maxChildren) {
              rejectReason = "Maximum child count exceeded for " + getDisplayName() + ".";
          } else {
              rejectReason = null;
          }
          
          return rejectReason == null;
      }