Add example of method complexity measurement
user
```ruby
$: << File.expand_path('../../lib', __FILE__)
require 'fast'

def node_size(node)
  return 1 unless node.respond_to?(:children)
  children = node.children
  return 1 if children.empty? || children.length == 1
  nodes, syms = children.partition{|e| e.respond_to?(:children) }
  1 + syms.length + (nodes.map(&method(:node_size)).inject(:+) || 0)
end

def method_complexity(file)
  ast = Fast.ast_from_file(file)
  Fast.search(ast,'(class ...)').map do |node_class|
    manager_name = node_class.children.first.children.last

    defs = Fast.search(node_class,'(def !{initialize} ... ... )')

    defs.map do |node|
      complexity = node_size(node)
      method_name = node.children.first
      {"#{manager_name}##{method_name}" => complexity }
    end.inject(:merge) || {}
  end
end

files = ARGV || Dir['**/*.rb']

complexities = files.map(&method(:method_complexity)).flatten.inject(:merge!)

puts "| Method | Complexity |"
puts "| ------ | ---------- |"
complexities.sort_by{|_,v|-v}.map do |method, complexity|
  puts "| #{method} | #{complexity} |"
end
```
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