src/Validation.php
public function mainMessage($value = null) {
        if ($value !== null) {
            $this->mainMessage = $value;
            return $this;
        }

        return $this->mainMessage;
    }
public function mainMessage($value = null) {
        if ($value !== null) {
            $this->mainMessage = $value;
            return $this;
        }

        return $this->mainMessage;
    }
Gets the main error message for the validation.

@param string|null $value Pass a new main message or null to get the current main message.
@return Validation|string Returns the main message or $this for fluent sets.