<a href="#Type_declarations">type</a>,
<a href="#Type_parameter_declarations">type parameter</a>,
<a href="#Variable_declarations">variable</a>,
<a href="#Function_declarations">function</a>,
<a href="#Labeled_statements">label</a>, or
<a href="#Import_declarations">package</a>.
Every identifier in a program must be declared.
No identifier may be declared twice in the same block, and