code: public MultiRuntimeDefinitionBuilder addRuntime(final Configuration config, final String runtimeName){
      Validate.notNull(config, "runtime configuration module should not be null");
      Validate.isTrue(StringUtils.isNotBlank(runtimeName),
              "runtimeName should be non empty and non blank string");
      final AvroRuntimeDefinition rd = createRuntimeDefinition(config, runtimeName);
      this.runtimes.put(runtimeName, rd);
      return this;
    }
docs: Adds runtime configuration module to the builder.
  @param config The configuration module
  @param runtimeName The name of the runtime
  @return The builder instance