diff --git a/spacy/kb/kb.pyx b/spacy/kb/kb.pyx
index ce4bc0138..72ee5283e 100644
--- a/spacy/kb/kb.pyx
+++ b/spacy/kb/kb.pyx
@@ -11,8 +11,9 @@ from ..errors import Errors
 
 
 cdef class KnowledgeBase:
-    """A `KnowledgeBase` instance stores unique identifiers for entities and their textual aliases,
-    to support entity linking of named entities to real-world concepts.
+    """A `KnowledgeBase` instance stores unique identifiers for entities and
+    their textual aliases, to support entity linking of named entities to
+    real-world concepts.
     This is an abstract class and requires its operations to be implemented.
 
     DOCS: https://spacy.io/api/kb
@@ -30,10 +31,13 @@ cdef class KnowledgeBase:
         self.entity_vector_length = entity_vector_length
         self.mem = Pool()
 
-    def get_candidates_batch(self, mentions: Iterable[Span]) -> Iterable[Iterable[Candidate]]:
+    def get_candidates_batch(
+        self, mentions: Iterable[Span]
+    ) -> Iterable[Iterable[Candidate]]:
         """
-        Return candidate entities for specified texts. Each candidate defines the entity, the original alias,
-        and the prior probability of that alias resolving to that entity.
+        Return candidate entities for specified texts. Each candidate defines
+        the entity, the original alias, and the prior probability of that
+        alias resolving to that entity.
         If no candidate is found for a given text, an empty list is returned.
         mentions (Iterable[Span]): Mentions for which to get candidates.
         RETURNS (Iterable[Iterable[Candidate]]): Identified candidates.
@@ -42,14 +46,17 @@ cdef class KnowledgeBase:
 
     def get_candidates(self, mention: Span) -> Iterable[Candidate]:
         """
-        Return candidate entities for specified text. Each candidate defines the entity, the original alias,
+        Return candidate entities for specified text. Each candidate defines
+        the entity, the original alias,
         and the prior probability of that alias resolving to that entity.
         If the no candidate is found for a given text, an empty list is returned.
         mention (Span): Mention for which to get candidates.
         RETURNS (Iterable[Candidate]): Identified candidates.
         """
         raise NotImplementedError(
-            Errors.E1045.format(parent="KnowledgeBase", method="get_candidates", name=self.__name__)
+            Errors.E1045.format(
+                parent="KnowledgeBase", method="get_candidates", name=self.__name__
+            )
         )
 
     def get_vectors(self, entities: Iterable[str]) -> Iterable[Iterable[float]]:
@@ -67,7 +74,9 @@ cdef class KnowledgeBase:
         RETURNS (Iterable[float]): Vector for specified entity.
         """
         raise NotImplementedError(
-            Errors.E1045.format(parent="KnowledgeBase", method="get_vector", name=self.__name__)
+            Errors.E1045.format(
+                parent="KnowledgeBase", method="get_vector", name=self.__name__
+            )
         )
 
     def to_bytes(self, **kwargs) -> bytes:
@@ -75,7 +84,9 @@ cdef class KnowledgeBase:
         RETURNS (bytes): Current state as binary string.
         """
         raise NotImplementedError(
-            Errors.E1045.format(parent="KnowledgeBase", method="to_bytes", name=self.__name__)
+            Errors.E1045.format(
+                parent="KnowledgeBase", method="to_bytes", name=self.__name__
+            )
         )
 
     def from_bytes(self, bytes_data: bytes, *, exclude: Tuple[str] = tuple()):
@@ -84,25 +95,35 @@ cdef class KnowledgeBase:
         exclude (Tuple[str]): Properties to exclude when restoring KB.
         """
         raise NotImplementedError(
-            Errors.E1045.format(parent="KnowledgeBase", method="from_bytes", name=self.__name__)
+            Errors.E1045.format(
+                parent="KnowledgeBase", method="from_bytes", name=self.__name__
+            )
         )
 
-    def to_disk(self, path: Union[str, Path], exclude: Iterable[str] = SimpleFrozenList()) -> None:
+    def to_disk(
+            self, path: Union[str, Path], exclude: Iterable[str] = SimpleFrozenList()
+    ) -> None:
         """
         Write KnowledgeBase content to disk.
         path (Union[str, Path]): Target file path.
         exclude (Iterable[str]): List of components to exclude.
         """
         raise NotImplementedError(
-            Errors.E1045.format(parent="KnowledgeBase", method="to_disk", name=self.__name__)
+            Errors.E1045.format(
+                parent="KnowledgeBase", method="to_disk", name=self.__name__
+            )
         )
 
-    def from_disk(self, path: Union[str, Path], exclude: Iterable[str] = SimpleFrozenList()) -> None:
+    def from_disk(
+            self, path: Union[str, Path], exclude: Iterable[str] = SimpleFrozenList()
+    ) -> None:
         """
         Load KnowledgeBase content from disk.
         path (Union[str, Path]): Target file path.
         exclude (Iterable[str]): List of components to exclude.
         """
         raise NotImplementedError(
-            Errors.E1045.format(parent="KnowledgeBase", method="from_disk", name=self.__name__)
+            Errors.E1045.format(
+                parent="KnowledgeBase", method="from_disk", name=self.__name__
+            )
         )