static void populateConnectionAttributes(final Map<AttributeKey<?>, Object> attributes,
    final Supplier<String> connectionStringSupplier, final Supplier<User> userSupplier) {
    attributes.put(DB_SYSTEM, DB_SYSTEM_VALUE);
    attributes.put(DB_CONNECTION_STRING, connectionStringSupplier.get());
    attributes.put(DB_USER,
      Optional.ofNullable(userSupplier.get()).map(Object::toString).orElse(null));
  }
Static utility method that performs the primary logic of this builder. It is visible to other
classes in this package so that other builders can use this functionality as a mix-in.
@param attributes               the attributes map to be populated.
@param connectionStringSupplier the source of the {@code db.connection_string} attribute value.
@param userSupplier             the source of the {@code db.user} attribute value.
hbase-client/src/main/java/org/apache/hadoop/hbase/client/trace/ConnectionSpanBuilder.java