def getVlansByInterface(node,strInterfaceToAct):
    """
    Returns Vlans used on an interface.
    
    Author:
    David J. Stern

    Date:
    DEC 2017
    
    Parameters: 
    node: (YDK node): YDK node object
    strInterfaceToAct: (String): vendor interface name
    
    Returns:
    tagsInUse: (Array): cast to str if needed, will be an int[]
    """   
    tagsInUse=[]
    for i in node.trunks.trunk:
        intVlans=i.layer3_sub_interfaces.dot1q_count
    for i in node.tag_allocations.tag_allocation:
        if str(i.interface)==strInterfaceToAct:
            if tagsInUse.count==0: tagsInUse[0]=i.first_tag
            else: tagsInUse.append(i.first_tag)
    return tagsInUse