  from ..vocab cimport EMPTY_LEXEME
  from ..structs cimport Entity
  
  
  cdef class StateClass:
      def __init__(self, int length):
          cdef Pool mem = Pool()
 
</s> remove from ..attrs cimport TAG, HEAD, DEP, ENT_IOB, ENT_TYPE, IS_SPACE
 </s> add from ..attrs cimport TAG, HEAD, DEP, ENT_IOB, ENT_TYPE </s> remove         # Don't allow spaces to be the first word of a sentence
        elif Lexeme.c_check_flag(st.B_(0).lex, IS_SPACE):
            return False
 </s> add  </s> remove         while self.buffer_length() == 0 or self.stack_depth() == 0:
 </s> add         while self.buffer_length() == 0 \
        or self.stack_depth() == 0 \
        or Lexeme.c_check_flag(self.S_(0).lex, IS_SPACE): </s> remove @pytest.mark.xfail
 </s> add 
from ..lexeme cimport Lexeme
from ..symbols cimport punct
from ..attrs cimport IS_SPACE
  from ..vocab cimport EMPTY_LEXEME
  from ..structs cimport Entity
from ..lexeme cimport Lexeme
from ..symbols cimport punct
from ..attrs cimport IS_SPACE
  
  
  cdef class StateClass:
      def __init__(self, int length):
          cdef Pool mem = Pool()
keep add keep keep keep keep keep
 * Unwind limit to sentence boundary detection that prevents it from inserting boundaries on whitespace. Replace it with a check for whitespace in StateClass.fast_forward, so that whitespace is LeftArced when it's on the stack. This should prevent the previous problem of whitespace-only sentences. Should fix Issue #184, but may cause further problems. Needs testing. 
spacy/syntax/stateclass.pyx