code: function _customDefinitions (type, object) {
    var errors
  
    if (isFunction(definitions[type])) {
      try {
        errors = definitions[type](object)
      } catch (e) {
        errors = ['Problem with custom definition for '+type+': '+e]
      }
      if (typeof result === 'string') {
        errors = [errors]
      }
      if (Object.prototype.toString.call(errors) === '[object Array]') {
        return errors
      }
    }
    return []
  }
docs: calls a custom definition if one is avalible for the given type
  @method _customDefinitions
  @private
  @param type {'String'} a GeoJSON object type
  @param object {Object} the Object being tested
  @return {Array} an array of errors