FileCredentialsImpl(CredentialsScope, String, String, FileItem, String, SecretBytes)
FileCredentialsImpl(CredentialsScope, String, String, String, SecretBytes)
FileCredentialsImpl(CredentialsScope, String, String, FileItem, String, SecretBytes)
for stapler orFileCredentialsImpl(CredentialsScope, String, String, String, SecretBytes)
for programatic instantiation.