"Implements" a lazy val field whose initialization expression can refer to implicit context information of type Context. The "val" is initialized upon the first call to get, using the context information supplied for this call, like a lazy val.

Instead of a plain lazy val field without context

class C { lazy val f: T = initializer }

use the following code to pass in a Context:

class C {
  private[this] val _f: LazyValWithContext[T, Context] = new LazyValWithContext[T, Context](context => initializer)
  def f(implicit context: Context): T = _f.get
}

This class implements the same scheme as how the Scala 2.13 compiler implements lazy vals, as explained on https://docs.scala-lang.org/sips/improved-lazy-val-initialization.html (version V1) along with its caveats.