Function snippet_block_with_applicability 

pub fn snippet_block_with_applicability<'sm>(
    sm: impl HasSourceMap<'sm>,
    span: Span,
    default: &str,
    indent_relative_to: Option<Span>,
    applicability: &mut Applicability,
) -> String

Same as snippet_block, but adapts the applicability level by the rules of snippet_with_applicability.