code: def _check_solver(solver):
      all_solvers = ["SGD"]
      if solver not in all_solvers:
          raise ValueError(
              "Logistic Regression supports only solvers in %s, got"
              " %s." % (all_solvers, solver)
          )
      return solver
  
file_path: mars/mars/learn/glm/_logistic.py
imports: import numbers
  from sklearn.utils.validation import _deprecate_positional_args
  from ...None import tensor
  from ..linear_model._base import LinearClassifierMixin
  from ..base import BaseEstimator
  from ..utils.validation import check_is_fitted
  from ..utils.multiclass import check_classification_targets
  from ..utils.extmath import softmax
  from ._optimizers import gradient_descent
label_desc: Use image node_id 1 for calling a global function with example usage: _check_solver(solver) and returns: solver