Javadoc
Returns true if this item can be read (displayed).
In case of containers this flag is, strictly speaking, not applicable. Container is an
empty shell. What matters is access to individual sub-item. However, for containers this
value has a "hint" meaning. It means that the container itself contains something that is
readable. Which can be used as a hint by the presentation to display container label or block.
This usually happens if the container contains at least one readable item.
This does NOT mean that also all the container items can be displayed. The sub-item permissions
are controlled by similar properties on the items. This property only applies to the container
itself: the "shell" of the container.
Note: It was considered to use a different meaning for this flag - a meaning that would allow
canRead()=false containers to have readable items. However, this was found not to be very useful.
Therefore the "something readable inside" meaning was confirmed instead.