hollow/src/main/java/com/netflix/hollow/core/read/engine/object/HollowObjectTypeReadStateShard.java
public int bitsRequiredForField(String fieldName) {
        int fieldIndex = schema.getPosition(fieldName);
        return fieldIndex == -1 ? 0 : currentDataVolatile.bitsPerField[fieldIndex];
    }
public int bitsRequiredForField(String fieldName) {
        int fieldIndex = schema.getPosition(fieldName);
        return fieldIndex == -1 ? 0 : currentDataVolatile.bitsPerField[fieldIndex];
    }
Warning:  Not thread-safe.  Should only be called within the update thread.