Support blank lines before first method

In IDEA this setting actually only applies if the method is the first statement within the class, so this behavior has been duplicated.

Author: knutwannheden

rewrite/rewrite/python/format/blank_lines.py

@@ -52,6 +52,8 @@ def visit_statement(self, statement: Statement, p: P) -> J:
                     min_lines = max(min_lines, self._style.minimum.around_method)
                 elif not is_first and isinstance(statement, ClassDeclaration):
                     min_lines = max(min_lines, self._style.minimum.around_class)
+                elif is_first and isinstance(statement, MethodDeclaration):
+                    min_lines = max(min_lines, self._style.minimum.before_first_method)
             if prev_import:
                 min_lines = max(min_lines, self._style.minimum.after_local_imports)
             statement = minimum_lines_for_tree(statement, min_lines)

rewrite/tests/python/all/format/blank_lines_test.py

@@ -146,3 +146,44 @@ class Foo:
             from_visitor(BlankLinesVisitor(style))
         )
     )
+
+
+def test_before_first_method():
+    style = IntelliJ.blank_lines()
+    style = style.with_minimum(
+        style.minimum.with_before_first_method(2)
+    )
+    rewrite_run(
+        # language=python
+        python(
+            """\
+            class Foo:
+                def __init__(self):
+                    pass
+
+
+            class Bar:
+                x = 1
+                def __init__(self):
+                    pass
+            """,
+            """\
+            class Foo:
+
+
+                def __init__(self):
+                    pass
+
+
+            class Bar:
+                x = 1
+
+                def __init__(self):
+                    pass
+            """
+        ),
+        spec=RecipeSpec()
+        .with_recipes(
+            from_visitor(BlankLinesVisitor(style))
+        )
+    )