spyglass/src/main/java/com/linkedin/android/spyglass/mentions/MentionsEditable.java
@Nullable
    public MentionSpan getMentionSpanAtOffset(int index) {
        MentionSpan[] spans = getSpans(index, index, MentionSpan.class);
        return (spans != null && spans.length > 0) ? spans[0] : null;
    }
@Nullable
    public MentionSpan getMentionSpanAtOffset(int index) {
        MentionSpan[] spans = getSpans(index, index, MentionSpan.class);
        return (spans != null && spans.length > 0) ? spans[0] : null;
    }
Given an integer offset, return the {@link MentionSpan} located at the offset in the text of the
{@link android.widget.EditText}, if it exists. Otherwise, return null.

@param index integer offset in text

@return a {@link MentionSpan} located at index in text, or null