Function check 

pub fn check(palette: &PaletteDef, map: &PatternMapDef) -> Vec<Problem>

What is wrong with map as the one-bit look of palette (ADR-0008 §4), in this order:

• errors: a role of the palette with no patterns (Rule::Missing), a role of the map, a group or the text roles that the palette lacks (Rule::Unknown), two roles of one colour with different patterns (Rule::SharedColour), and two roles of a distinct group whose foregrounds look alike (Rule::Distinct, Pattern::looks_like);
• warnings: a text role that isn’t Black on White or White on Black (Rule::Text).