class_docstr: Scansion constants can be modified and passed into the constructor if desired.
docstr: Return a list of starting consonant positions.
docstr_tok: ["Return","a","list","of","starting","consonant","positions","."]
code: def _starting_consonants_only(self, letters: list) -> list:
      """Return a list of starting consonant positions."""
      for idx, letter in enumerate(letters):
          if not self._contains_vowels(
              letter
          ) and self._contains_consonants(letter):
              return [idx]
          if self._contains_vowels(letter):
              return []
          if self._contains_vowels(
              letter
          ) and self._contains_consonants(letter):
              return []
      return []
  
imports: import copy
  import logging
  import re
  from typing import List
  import cltk.prosody.lat.string_utils
  from cltk.prosody.lat.scansion_constants import ScansionConstants
label_desc: Use image node_id 10 for calling the Syllabifier obj's underlying member method code with example usage: obj._starting_consonants_only(letters) and returns: list, list, list, list