@Contract("_,_ -> this")
  public CallMapper<T> register(@NotNull CallMatcher matcher, @NotNull Function<? super PsiMethodCallExpression, ? extends T> handler) {
    return register(CallHandler.of(matcher, handler));
  }
@Contract("_,_ -> this")
  public CallMapper<T> register(@NotNull CallMatcher matcher, @NotNull Function<? super PsiMethodCallExpression, ? extends T> handler)