code: private LocalVariable getConnection(CodeBuilder b, LocalVariable capVar) {
          b.loadLocal(capVar);
          b.invokeInterface(TypeDesc.forClass(JDBCConnectionCapability.class),
                            "getConnection", TypeDesc.forClass(Connection.class), null);
          LocalVariable conVar = b.createLocalVariable("con", TypeDesc.forClass(Connection.class));
          b.storeLocal(conVar);
          return conVar;
      }
docs: Generates code to get connection from JDBCConnectionCapability and store
  it in a local variable.
  
  @param capVar reference to JDBCConnectionCapability