build method

Implementation

ChildSemanticsConfigurationsResult build() {
  assert(() {
    final Set<SemanticsConfiguration> seenConfigs = <SemanticsConfiguration>{};
    for (final SemanticsConfiguration config in <SemanticsConfiguration>[
      ..._mergeUp,
      ..._siblingMergeGroups.flattened,
    ]) {
      assert(
        seenConfigs.add(config),
        'Duplicated SemanticsConfigurations. This can happen if the same '
        'SemanticsConfiguration was marked twice in markAsMergeUp and/or '
        'markAsSiblingMergeGroup',
      );
    }
    return true;
  }());
  return ChildSemanticsConfigurationsResult._(_mergeUp, _siblingMergeGroups);
}