private @Nullable Element getCompilerConfig() {
    Element executionConfiguration =
      getPluginExecutionConfiguration("org.apache.maven.plugins", "maven-compiler-plugin", "default-compile");
    if (executionConfiguration != null) return executionConfiguration;
    return getPluginConfiguration("org.apache.maven.plugins", "maven-compiler-plugin");
  }
private @Nullable Element getCompilerConfig()