src/Dispatch/AppRunner.php
public function setVariable(string $name, $value, bool $as_instance = true)
    {
        $this->variables[$name] = $value;
        if (is_object($value))
            $this->instances[get_class($value)] = $value;
        return $this;
    }
public function setVariable(string $name, $value, bool $as_instance = true)
    {
        $this->variables[$name] = $value;
        if (is_object($value))
            $this->instances[get_class($value)] = $value;
        return $this;
    }
Assign a variable to make available to the app.

Depending on the type of controller, the variables are assigned in
various ways.  For a plain script, the variables are available directly
as their name. When the script contains a class, the variables may be
assigned to public properties of that class with the same name.

Additionally, they may be assigned to parameters to the controller
method. When $as_instance is set to true, an equal class name
is sufficient to perform the matching. When $as_instance is set to false,
class and name must be equal. This only works for objects.

@param string $name The name of the variable
@param string $value The value to assign
@param bool $as_instance To allow referencing this variable by class
@return AppRunner Provides fluent interface