Get a Dimension object by name or index.

        Args:
            dimension: Dimension to look up by name or integer index
            default (optional): Value returned if Dimension not found
            strict (bool, optional): Raise a KeyError if not found

        Returns:
            Dimension object for the requested dimension or default

def get_dimension(self, dimension, default=None, strict=False):
        """Get a Dimension object by name or index.

        Args:
            dimension: Dimension to look up by name or integer index
            default (optional): Value returned if Dimension not found
            strict (bool, optional): Raise a KeyError if not found

        Returns:
            Dimension object for the requested dimension or default
        """
        if dimension is not None and not isinstance(dimension, (int, basestring, Dimension)):
            raise TypeError('Dimension lookup supports int, string, '
                            'and Dimension instances, cannot lookup '
                            'Dimensions using %s type.' % type(dimension).__name__)
        all_dims = self.dimensions()
        if isinstance(dimension, int):
            if 0 <= dimension < len(all_dims):
                return all_dims[dimension]
            elif strict:
                raise KeyError("Dimension %r not found" % dimension)
            else:
                return default
        dimension = dimension_name(dimension)
        name_map = {dim.name: dim for dim in all_dims}
        name_map.update({dim.label: dim for dim in all_dims})
        name_map.update({util.dimension_sanitizer(dim.name): dim for dim in all_dims})
        if strict and dimension not in name_map:
            raise KeyError("Dimension %r not found." % dimension)
        else:
            return name_map.get(dimension, default)