Thetype exposes the following members.
The line is located before any #line directive and there is at least one #line directive present in this syntax tree. This enum value is used for C# only to enable the consumer to define how to interpret the lines before the first line directive.
The line is following a #line hidden directive.
The line is following a #line default directive or a #line directive with at least a line number. If there is no line directive at all, Visible is returned for all lines.