@Override
    public int getFrom() {
        if (children().isEmpty()) {
            return -1;
        }
        if (cachedFrom == Integer.MIN_VALUE) {
            calculateFrom();
        }
        return cachedFrom;
    }
Returns the character index where this {@link SpanNode} starts (inclusive), i.e.&nbsp;the smallest {@link com.yahoo.document.annotation.SpanNode#getFrom()} of all children.

@return the lowest getFrom() of all children, or -1 if this SpanList has no children.
document/src/main/java/com/yahoo/document/annotation/SpanList.java