src/Route.php
public function mappings($mappings = null) {
        if ($this->mappings === null) {
            $this->mappings = [];
        }

        if (is_array($mappings)) {
            $mappings = array_change_key_case($mappings);

            $this->mappings = array_replace(
                $this->mappings,
                $mappings
            );
            return $this;
        }

        return $this->mappings;
    }
public function mappings($mappings = null) {
        if ($this->mappings === null) {
            $this->mappings = [];
        }

        if (is_array($mappings)) {
            $mappings = array_change_key_case($mappings);

            $this->mappings = array_replace(
                $this->mappings,
                $mappings
            );
            return $this;
        }

        return $this->mappings;
    }
Gets or sets the mappings array that maps parameter names to mappings.

@param array|null $mappings An array of mappings to set.
@return Route|array Returns the current mappings or `$this` for fluent calls.