public String getTag() {
    return mTag;
  }
Context chain that adds additional metadata about the current product and infra that's active.
These can be chained together, which allows us to identify a given product / infra.

<p>Each element in the chain is a simple tag / value pair. Tags can be arbitrary strings that can
be used to filter later on. For example, for product metadata, use {@link #TAG_PRODUCT}, for
infra {@link #TAG_INFRA} and for both (e.g. if you'd like to report the parent surface, like feed
or profile) {@link #TAG_PRODUCT_AND_INFRA}.

<p>The context chain can be serialized and used for logging. An example for a serialized chain:
"pi:FEED/p:feature_x/i:HeaderComponentSpec/p:profile_photo/i:MyFrescoImage"
fbcore/src/main/java/com/facebook/common/callercontext/ContextChain.java