module Hashie::Extensions::Coercion::InstanceMethods

def []=(key, value)
  into = self.class.key_coercion(key) || self.class.value_coercion(value)
  if value && into
    if into.respond_to?(:coerce)
      value = into.coerce(value)
    else
      value = into.new(value)
    end
  end
  super(key, value)
end

def custom_writer(key, value, convert = true)
  self[key] = value
end

def replace(other_hash)
  (keys - other_hash.keys).each { |key| delete(key) }
  other_hash.each { |key, value| self[key] = value }
  self
end