code: public ClassSymbol loadClass(ModuleSymbol msym, Name flatname) throws CompletionFailure {
          Assert.checkNonNull(msym);
          Name packageName = Convert.packagePart(flatname);
          PackageSymbol ps = syms.lookupPackage(msym, packageName);
  
          Assert.checkNonNull(ps.modle, () -> "msym=" + msym + "; flatName=" + flatname);
  
          boolean absent = syms.getClass(ps.modle, flatname) == null;
          ClassSymbol c = syms.enterClass(ps.modle, flatname);
  
          if (c.members_field == null) {
              try {
                  c.complete();
              } catch (CompletionFailure ex) {
                  if (absent) syms.removeClass(ps.modle, flatname);
                  throw ex;
              }
          }
          return c;
      }
docs: Load a toplevel class with given fully qualified name
  The class is entered into `classes' only if load was successful.