This package provides only two macros viz. \TheKey and
\TheValue to define then use pairs of key/value and gives a
semblance of a hash. Syntax: \TheKey{key}{value} to define the
value associated to the key, does not produce text;
\TheValue{key} to return the value linked to the key. Both
arguments of \TheKey are 'moving' as LaTeX defines the term and
we have sometimes to protect them.