class_docstr: Raised if a namespace doesn't exist.
code: def __init__(self, value):
      super().__init__(value)
      self.value = value
  
imports: import re
  from collections import namedtuple
  import guild
  from guild.entry_point_util import EntryPointResources
label_desc: Use image node_id 1 to create a new NamespaceError object from inherited base classes: LookupError with example: obj = NamespaceError(value)