code: @Nonnull
    public JSVar var (@Nonnull @Nonempty final String sName,
                      @Nullable final IJSExpression aInitExpression) throws JSNameAlreadyExistsException
    {
      final JSVar aVar = new JSVar (sName, aInitExpression);
      return addDeclaration (aVar);
    }
docs: Adds a local variable declaration to this block
  
  @param sName
  Name of the variable
  @param aInitExpression
  Initialization expression for this variable. May be null.
  @return Newly generated {@link JSVar}
  @throws JSNameAlreadyExistsException
  if the name is not unique