Add tests for names for lesser blocks.

src/types/lesser_element.rs

@@ -24,7 +24,7 @@ pub struct TableCell<'s> {
 #[derive(Debug)]
 pub struct VerseBlock<'s> {
     pub source: &'s str,
-    pub name: &'s str,
+    pub name: Option<&'s str>,
     pub data: Option<&'s str>,
     pub children: Vec<Object<'s>>,
 }
@@ -32,6 +32,7 @@ pub struct VerseBlock<'s> {
 #[derive(Debug)]
 pub struct CommentBlock<'s> {
     pub source: &'s str,
+    pub name: Option<&'s str>,
     pub contents: &'s str,
 }
 
@@ -48,6 +49,7 @@ pub enum RetainLabels {
 #[derive(Debug)]
 pub struct ExampleBlock<'s> {
     pub source: &'s str,
+    pub name: Option<&'s str>,
     pub switches: Option<&'s str>,
     pub number_lines: Option<SwitchNumberLines>,
     pub preserve_indent: Option<CharOffsetInLine>,
@@ -60,7 +62,7 @@ pub struct ExampleBlock<'s> {
 #[derive(Debug)]
 pub struct ExportBlock<'s> {
     pub source: &'s str,
-    pub name: &'s str,
+    pub name: Option<&'s str>,
     pub data: Option<&'s str>,
     pub contents: &'s str,
 }
@@ -68,6 +70,7 @@ pub struct ExportBlock<'s> {
 #[derive(Debug)]
 pub struct SrcBlock<'s> {
     pub source: &'s str,
+    pub name: Option<&'s str>,
     pub language: Option<&'s str>,
     pub switches: Option<&'s str>,
     pub parameters: Option<&'s str>,