public static TwitterResponse<TwitterUser> CheckMembership(
	OAuthTokens tokens,
	string ownerUsername,
	string listId,
	decimal userId,
	OptionalProperties options
)

Public Shared Function CheckMembership ( _
	tokens As OAuthTokens, _
	ownerUsername As String, _
	listId As String, _
	userId As Decimal, _
	options As OptionalProperties _
) As TwitterResponse(Of TwitterUser)