src/Action/InNestedArray.php
public function setValueMutator(callable $callback) : self
    {
        $this->valueMutator = $callback;
        $this->value = ($this->valueMutator)($this->value);
        return $this;
    }
public function setValueMutator(callable $callback) : self
    {
        $this->valueMutator = $callback;
        $this->value = ($this->valueMutator)($this->value);
        return $this;
    }
Set callback function for changing values before compare.

@param callable $callback
@return InNestedArray