Fix issues noted in 18484 (#18824)

doc/stdlib/base.rst

@@ -854,6 +854,35 @@ Nullables
  julia> isnull(x)
  false
 
+.. function:: unsafe_get(x)
+
+ .. Docstring generated from Julia source
+
+ Return the value of ``x`` for :obj:`Nullable` ``x``\ ; return ``x`` for all other ``x``\ .
+
+ This method does not check whether or not ``x`` is null before attempting to access the value of ``x`` for ``x::Nullable`` (hence "unsafe").
+
+ .. doctest::
+
+ julia> x = Nullable(1)
+ Nullable{Int64}(1)
+
+ julia> unsafe_get(x)
+ 1
+
+ julia> x = Nullable{String}()
+ Nullable{String}()
+
+ julia> unsafe_get(x)
+ ERROR: UndefRefError: access to undefined reference
+ in unsafe_get(::Nullable{String}) at ./REPL[4]:1
+
+ julia> x = 1
+ 1
+
+ julia> unsafe_get(x)
+ 1
+
 System
 ------