code: def buildType(columns=[], extra=[]):
          
          return Type(id="epics:nt/NTTable:1.0",
                      spec=[
                      ('labels', 'as'),
                      ('value', ('S', None, columns)),
                      ('descriptor', 's'),
                      ('alarm', alarm),
                      ('timeStamp', timeStamp),
                      ] + extra)
docs: Build a table
  
          :param list columns: List of column names and types. eg [('colA', 'd')]
          :param list extra: A list of tuples describing additional non-standard fields
          :returns: A :py:class:`Type`