*/ public array $columns = []; /** * Set the unique index which caused the violation. * * @param string|null $index * @return $this */ public function setIndex(?string $index): self { $this->index = $index; return $this; } /** * Set the columns that caused the violation. * * @param list $columns * @return $this */ public function setColumns(array $columns): self { $this->columns = $columns; return $this; } }