text: 'use strict'
  
  var extend = require('util')._extend
    , jsonSafeStringify = require('json-stringify-safe')
    , crypto = require('crypto')
  
  function deferMethod() {
    if(typeof setImmediate === 'undefined') {
      return process.nextTick
    }
  
    return setImmediate
  }
  
  function constructObject(initialObject) {
    initialObject = initialObject || {}
  
    return {
      extend: function (object) {
        return constructObject(extend(initialObject, object))
      },
      done: function () {
        return initialObject
      }
    }
  }
  
  function constructOptionsFrom(uri, options) {
    var params = constructObject()
    if (typeof options === 'object') {
      params.extend(options).extend({uri: uri})
    } else if (typeof uri === 'string') {
      params.extend({uri: uri})
    } else {
      params.extend(uri)
    }
    return params.done()
  }
  
  function isFunction(value) {
    return typeof value === 'function'
  }
  
  function filterForCallback(values) {
    var callbacks = values.filter(isFunction)
    return callbacks[0]
  }
  
  function paramsHaveRequestBody(params) {
    return (
      params.options.body ||
      params.options.requestBodyStream ||
      (params.options.json && typeof params.options.json !== 'boolean') ||
      params.options.multipart
    )
  }
  
  function safeStringify (obj) {
    var ret
    try {
      ret = JSON.stringify(obj)
    } catch (e) {
      ret = jsonSafeStringify(obj)
    }
    return ret
  }
  
  function md5 (str) {
    return crypto.createHash('md5').update(str).digest('hex')
  }
  
  function isReadStream (rs) {
    return rs.readable && rs.path && rs.mode
  }
  
  function toBase64 (str) {
    return (new Buffer(str || '', 'utf8')).toString('base64')
  }
  
  exports.isFunction            = isFunction
  exports.constructObject       = constructObject
  exports.constructOptionsFrom  = constructOptionsFrom
  exports.filterForCallback     = filterForCallback
  exports.paramsHaveRequestBody = paramsHaveRequestBody
  exports.safeStringify         = safeStringify
  exports.md5                   = md5
  exports.isReadStream          = isReadStream
  exports.toBase64              = toBase64
  exports.defer                 = deferMethod()
  