lib/transform/standardize.js
function mustBeString(filter, keyword, field) {
  if (typeof filter[field] !== 'string') {
    return Bluebird.reject(new BadRequestError(`Attribute "${field}" in "${keyword}" must be a string`));
  }

  return Bluebird.resolve();
}
function mustBeString(filter, keyword, field) {
  if (typeof filter[field] !== 'string') {
    return Bluebird.reject(new BadRequestError(`Attribute "${field}" in "${keyword}" must be a string`));
  }

  return Bluebird.resolve();
}
function mustBeString ( filter , keyword , field ) { if ( typeof filter [ field ] !== 'string' ) { return Bluebird . reject ( new BadRequestError ( ` ${ field } ${ keyword } ` ) ) ; } return Bluebird . resolve ( ) ; }
Verifies that filter.field is a string
@param filter
@param keyword
@param field
@returns {Promise}
Verifies that filter . field is a string