public static Long parseDurationString(final String str) throws NumberFormatException {
        return parseNumberString(str, TIME_SIZE_DIVIDER);
    }
Parses human-readable time durations that use time units into milliseconds.
Only supports integer/long values.
e.g. '10s' => 10_000, '10' => 10. The case of the unit prefixes is ignored.
Valid unit prefixes (case-insensitive) are:
<pre>{@code "ms"}</pre>
<pre>{@code "s"}</pre>
<pre>{@code "m"}</pre>
<pre>{@code "h"}</pre>
<pre>{@code "d"}</pre>
If there is no unit prefix then the number is assumed to be in millis and is
converted from the string as is.

@return The number or null for a null/empty input.
@throws NumberFormatException If it can't be parsed.
stroom-util-shared/src/main/java/stroom/util/shared/ModelStringUtil.java