default refresh cycle for FileBackedHTTPMetadataProvider

[Tom Scavo]

Does a FileBackedHTTPMetadataProvider default to some refresh cycle?

For example:

<MetadataProvider id="URLMD_incommon"
xsi:type="FileBackedHTTPMetadataProvider"
metadataURL="http://md.incommon.org/InCommon/InCommon-metadata.xml"
backingFile="/opt/shibboleth-idp/metadata/InCommon_metadata.xml"/>

No refresh parameters are given. Is the file refreshed according to
some default cycle?

Thanks in advance,

Tom