Attempt to document method 'of' in class Hash

gistfile1.txt

=head2 method of

Defined as:

    method of 

Usage:

    Hash.of

Returns the type constraint for the values of the invocant. By default,
i.e. if no type constraint is given during declaration, the method 
returns C<(Mu)>.

    my %h1 = 'apples' => 3, 'oranges' => 7;  # (no type constraint specified)
    say %h1.of;                              # (Mu)

    my Int %h2 = 'oranges' => 7;             # (values must be of type Int)
    say %h2.of;                              # (Int)