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diff --git a/mmi2grpc/_helpers.py b/mmi2grpc/_helpers.py
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+++ b/mmi2grpc/_helpers.py
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+# Copyright 2022 Google LLC
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     https://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+"""Helper functions.
+
+Facilitates the implementation of a new profile proxy or a PTS MMI.
+"""
+
+import functools
+import textwrap
+import unittest
+
+DOCSTRING_WIDTH = 80 - 8  # 80 cols - 8 indentation spaces
+
+
+def assert_description(f):
+    """Decorator which verifies the description of a PTS MMI implementation.
+
+    Asserts that the docstring of a function implementing a PTS MMI is the same
+    as the corresponding official MMI description.
+
+    Args:
+        f: function implementing a PTS MMI.
+
+    Raises:
+        AssertionError: the docstring of the function does not match the MMI
+            description.
+    """
+    @functools.wraps(f)
+    def wrapper(*args, **kwargs):
+        description = textwrap.fill(
+            kwargs['description'], DOCSTRING_WIDTH, replace_whitespace=False)
+        docstring = textwrap.dedent(f.__doc__ or '')
+
+        if docstring.strip() != description.strip():
+            print(f'Expected description of {f.__name__}:')
+            print(description)
+
+            # Generate AssertionError.
+            test = unittest.TestCase()
+            test.maxDiff = None
+            test.assertMultiLineEqual(
+                docstring.strip(),
+                description.strip(),
+                f'description does not match with function docstring of'
+                f'{f.__name__}')
+
+        return f(*args, **kwargs)
+    return wrapper
+
+
+def format_function(mmi_name, mmi_description):
+    """Returns the base format of a function implementing a PTS MMI."""
+    wrapped_description = textwrap.fill(
+        mmi_description, DOCSTRING_WIDTH, replace_whitespace=False)
+    return (
+        f'@assert_description\n'
+        f'def {mmi_name}(self, **kwargs):\n'
+        f'    """\n'
+        f'{textwrap.indent(wrapped_description, "    ")}\n'
+        f'    """\n'
+        f'\n'
+        f'    return "OK"\n')
+
+
+def format_proxy(profile, mmi_name, mmi_description):
+    """Returns the base format of a profile proxy including a given MMI."""
+    wrapped_function = textwrap.indent(
+        format_function(mmi_name, mmi_description), '    ')
+    return (
+        f'from mmi2grpc._helpers import assert_description\n'
+        f'from mmi2grpc._proxy import ProfileProxy\n'
+        f'\n'
+        f'from pandora.{profile.lower()}_grpc import {profile}\n'
+        f'\n'
+        f'\n'
+        f'class {profile}Proxy(ProfileProxy):\n'
+        f'\n'
+        f'    def __init__(self, channel):\n'
+        f'        super().__init__()\n'
+        f'        self.{profile.lower()} = {profile}(channel)\n'
+        f'\n'
+        f'{wrapped_function}')