code: private Environment checkBlock(Stmt.Block block, Environment environment, EnclosingScope scope) {
  		for (int i = 0; i != block.size(); ++i) {
  			Stmt stmt = block.get(i);
  			environment = checkStatement(stmt, environment, scope);
  		}
  		return environment;
  	}
docs: check type information in a flow-sensitive fashion through a block of
  statements, whilst type checking each statement and expression.
  
  @param block
  Block of statements to flow sensitively type check
  @param environment
  Determines the type of all variables immediately going into this
  block
  @return