@Override
  public @NotNull String filterModifier(@NotNull String varName, @NotNull ColumnFilter filter) {
    if (filter.isSubstring()) {
      return String.format("%1$s[%1$s.apply(str).str.contains('%2$s', regex=%3$s)]",
                           varName, filter.getFilter(), filter.isRegex() ? "True" : "False");
    }

    return String.format("%1$s[%1$s.apply(lambda %3$s: bool(%2$s))]", varName, filter.getFilter(), ColumnFilter.VAR_ALIAS);
  }
@Override
  public @NotNull String filterModifier(@NotNull String varName, @NotNull ColumnFilter filter)