All values in an eno document, such as the value of a field like
the value of a block, the value of a list item, the value of a fieldset
entry, and so on, map to an
Eno::Field. Usually you don't interact with this
because you directly get the values from a section or fieldset in most cases.
When you sequentially iterate a section (with
#elements method) you will get to interact with this class.