0 400   0   # Simple nesting
 0 400   0   f" { "" } "
 1 400   0   
 0 400   0   # Multi-line field with comment
 0 400   0   f" {
 1 400   0   
 0 400   0   "" # comment
 1 400   0   
 0 400   0   } "
 1 400   0   
 0 400   0   # Single quoted continued with \
 0 400   0   f" \
 0 400   0   "
 1 400   0   
 0 400   0   # 4 nested f-strings
 0 400   0   f'Outer {f"nested {1} {f"nested {2} {f"nested {3} {f"nested {4}"}"}"}"}'
 1 400   0