class_docstr: Interface for simple dictionary-based dataset format. The dictionary
  keys correspond to the column (i.e. dimension) names and the values
  are collections representing the values in that column.
class_docstr_tok: ["Interface","for","simple","dictionary-based","dataset","format",".","The","dictionary","keys","correspond","to","the","column","(","i.e",".","dimension",")","names","and","the","values","are","collections","representing","the","values","in","that","column","."]
code: def add_dimension(cls, dataset, dimension, dim_pos, values, vdim):
      dim = dimension_name(dimension)
      data = list(dataset.data.items())
      data.insert(dim_pos, (dim, values))
      return dict(data)
  
imports: from collections import OrderedDict, defaultdict
  import numpy
  from ..None import util
  from ..dimension import dimension_name
  from ..element import Element
  from ..ndmapping import NdMapping, item_check, sorted_context
  from ..util import isscalar
  from .interface import DataError, Interface
label_desc: Use image node_id 9 for calling the DictInterface obj's underlying member method code with example usage: obj.add_dimension(cls, dataset, dimension, dim_pos, values, vdim) and returns: dict