class_docstr: A setting for entering text values limited to alphanumeric + _ values
  
  This can be used for measurement names, object names, etc.
docstr: Restrict names to legal ascii C variables
  
  First letter = a-zA-Z and underbar, second is that + digit.
docstr_tok: ["Restrict","names","to","legal","ascii","C","variables","First","letter","=","a-zA-Z","and","underbar",",","second","is","that","+","digit","."]
code: def test_valid(self, pipeline):
      """Restrict names to legal ascii C variables
  
      First letter = a-zA-Z and underbar, second is that + digit.
      """
      self.validate_alphanumeric_text(
          self.value, self, self.first_must_be_alpha
      )
  
imports: import re
  from .._text import Text
  from ..._validation_error import ValidationError
label_desc: Use image node_id 2 for calling the Alphanumeric obj's underlying member method code with example usage: obj.test_valid(pipeline) without return types