add FileSet method to siaFileSetEntry

Status Job ID Name Coverage
  Lint
passed #200891113
lint

00:04:18

 
  Test
passed #200891117
integration-tests

00:21:59

75.0%
passed #200891114
legacy-tests

00:07:26

47.5%
passed #200891115
package-tests

00:17:19

87.0%