code: function shouldHide(schema, options, target, doc, transformed, pathname) {
    let hideTarget = hide + target
  
    // Is hiding turned off?
    if (options[hideTarget] === false) {
      return false
    }
  
    // Test hide by option or schema
    return (
      testOptions(options, pathname)
      || testSchema(schema, hide, doc, transformed)
      || testSchema(schema, hideTarget, doc, transformed)
    )
  }
docs: Should a property be hidden er not
  
  @access private
  @param {Schema} schema a mongoose schema
  @param {object} options a set of options
  @param {string} target the target to test, e.g 'JSON'
  @param {object} doc original document
  @param {object} transformed transformed document
  @param {string} pathname property path
  @returns {Boolen} true of pathname should be hidden