Timelines are series of psychTestR test elements that chain together to form a test. They support internationalisation, defining parallel series of test elements for the available languages.

## Creation

Timelines are created using new_timeline.

## Manipulation

Timelines can be combined with other timelines and with test elements using c.

## Usage

Timelines are ultimately passed to make_test.

## Other methods

x$get(language, i) returns a list of test elements corresponding to language as extracted from the timeline x, or, if i is not NULL, the ith such test element. x$drop_languages(drop) removes support for a set of languages from timeline x, where drop is the character vector of languages to remove.

## Methods

### Method clone()

The objects of this class are cloneable with this method.

#### Usage

timeline\$clone(deep = FALSE)

#### Arguments

deep

Whether to make a deep clone.