code: @NonNull
      public static On innerJoin(@NonNull DataSource datasource) {
          if (datasource == null) {
              throw new IllegalArgumentException("datasource cannot be null.");
          }
          return new On(Type.INNER, datasource);
      }
docs: Create an INNER JOIN component with the given data source.
  Use the returned On component to specify join conditions.
  
  @param datasource The DataSource object of the JOIN clause.
  @return The On object used for specifying join conditions.