shadows/framework/src/main/java/org/robolectric/shadows/ShadowTrace.java
@Implementation(minSdk = JELLY_BEAN_MR2)
  protected static void beginSection(String sectionName) {
    if (Trace.isTagEnabled(TRACE_TAG_APP)) {
      if (crashOnIncorrectUsage) {
        if (sectionName.length() > MAX_SECTION_NAME_LEN) {
          throw new IllegalArgumentException("sectionName is too long");
        }
      } else if (sectionName == null) {
        Log.w(TAG, "Section name cannot be null");
        return;
      } else if (sectionName.length() > MAX_SECTION_NAME_LEN) {
        Log.w(TAG, "Section name is too long");
        return;
      }

      synchronized (lock) {
        currentSections.addFirst(sectionName);
      }
    }
  }
@Implementation(minSdk = JELLY_BEAN_MR2)
  protected static void beginSection(String sectionName) {
    if (Trace.isTagEnabled(TRACE_TAG_APP)) {
      if (crashOnIncorrectUsage) {
        if (sectionName.length() > MAX_SECTION_NAME_LEN) {
          throw new IllegalArgumentException("sectionName is too long");
        }
      } else if (sectionName == null) {
        Log.w(TAG, "Section name cannot be null");
        return;
      } else if (sectionName.length() > MAX_SECTION_NAME_LEN) {
        Log.w(TAG, "Section name is too long");
        return;
      }

      synchronized (lock) {
        currentSections.addFirst(sectionName);
      }
    }
  }
Starts a new trace section with given name.