@deprecated, ReplaceWith documentation

Is there any documentation on the language used in `ReplaceWith`? It feels like a custom language on which I can seem to find any spec or documentation apart from the blog post announcing it.

According to javadoc it should be code snippet on Kotlin: /** * Specifies a code fragment that can be used to replace a deprecated function or property. Tools such * as IDEs can automatically apply the replacements specified through this annotation. * * @property expression the replacement expression. The replacement expression is interpreted in the context *   of the function or property being called, and can reference members of enclosing classes etc. *   For function calls, the replacement expression may contain argument names of the deprecated function, *   which will be substituted with actual parameters used in the call being updated. The imports used in the file *   containing the deprecated function or property are NOT accessible; if the replacement expression refers *   on any of those imports, they need to be specified explicitly in the [imports] parmeter. * @property imports the qualified names that need to be imported in order for the references in the *   replacement expression to be resolved correctly. */

target()

public annotation(retention = BINARY, mustBeDocumented = true) class ReplaceWith(val expression: String, vararg val imports: String)