A map literal, {k: v, ?k2: v2}.
Each entry has its key and value nodes; optional is true for an
entry written with ?, which is added only when its optional value is
present.
Summary
Types
@type t() :: %CEL.Expr.MapLiteral{ entries: [CEL.Expr.map_entry()], id: CEL.Checked.expr_id(), type: CEL.Expr.type() }