how do I remove fab bottom padding in scaffold

Question

widgets used as fab in a scaffold
seem to have padding by default

see dartpad example

import 'package:flutter/material.dart';

void main() => runApp(
      MaterialApp(
        home: Scaffold(
          floatingActionButtonLocation:
              FloatingActionButtonLocation.centerFloat,
          floatingActionButton: Padding(
            padding: EdgeInsets.zero,
            child: Container(height: 56, color: Colors.red),
          ),
        ),
      ),
    );

how do I remove the padding at the bottom of the red container?

the current (lame) workaround being

import 'package:flutter/material.dart';

void main() => runApp(
      MaterialApp(
        home: Scaffold(
          floatingActionButtonLocation:
              FloatingActionButtonLocation.centerFloat,
+         bottomSheet: Container(height: 16, color: Colors.red),
          floatingActionButton: Padding(
            padding: EdgeInsets.zero,
            child: Container(height: 56, color: Colors.red),
          ),
        ),
      ),
    );

Answer 1

Just change floatingActionButton location:

floatingActionButtonLocation: 
              FloatingActionButtonLocation.centerFloat

to

floatingActionButtonLocation:
              FloatingActionButtonLocation.centerDocked,

result: