return str == null ? defaultStr : str;
    }

    /**
     * <p>Checks if the CharSequence contains only ASCII printable characters.</p>
     *
     * <p>{@code null} will return {@code false}.
     * An empty CharSequence (length()=0) will return {@code true}.</p>
     *
     * <pre>
     * StringUtils.isAsciiPrintable(null)     = false
     * StringUtils.isAsciiPrintable("")       = true

# The size of one page for paging
paging.page.size = 25

# The size of page range for paging
paging.page.range.size = 5

# The option 'fillLimit' of page range for paging
paging.page.range.fill.limit = true

# fetch page size
page.docboost.max.fetch.size=1000
page.keymatch.max.fetch.size=1000
page.labeltype.max.fetch.size=1000
page.roletype.max.fetch.size=1000
page.user.max.fetch.size=1000