Feature: Isophase Lights

Isophase lights (Iso) are equally dark and light

Scenario Outline: Isophase Period <character>

The cycle period of an isophase light is divided evenly between the light and dark periods

When I request an image with the characteristic <character>

Then the first frame is <colour> for <period> seconds

And the next frame is transparent for <period> seconds

Examples:

character	colour	period
Iso W 6	white	3
Iso R 10	red	5
Iso G 7	green	3.5
Iso Y 8	yellow	4