public Builder nameFilter(final String nameFilter) {
            final String filter = NullSafe.get(
                    nameFilter,
                    String::trim,
                    str -> str.length() == 0
                            ? null
                            : str);
            this.nameFilter = filter;
            this.nameFilterChange = true;
            return this;
        }
This sets the name filter to be used when fetching items. This method
returns false is the filter is set to the same value that is already set.
stroom-core-shared/src/main/java/stroom/explorer/shared/ExplorerTreeFilter.java