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Co-authored-by: kernc <[email protected]>

Author: ivaigult

backtesting/backtesting.py

@@ -91,8 +91,8 @@ def I(self,  # noqa: E743
 
         In the plot legend, the indicator is labeled with
         function name, unless `name` overrides it. If `func` returns
-        multiple arrays, `name` can be a collection of strings, and
-        the size must agree with the number of arrays returned.
+        multiple arrays, `name` can be a sequence of strings, and
+        its size must agree with the number of arrays returned.
 
         If `plot` is `True`, the indicator is plotted on the resulting
         `backtesting.backtesting.Backtest.plot`.
@@ -130,8 +130,7 @@ def _format_name(name: str) -> str:
         elif try_(lambda: all(isinstance(item, str) for item in name), False):
             name = [_format_name(item) for item in name]
         else:
-            raise TypeError(f'Unexpected `name` type {type(name)}, `str` or `Iterable[str]` '
-                            'was expected.')
+            raise TypeError(f'Unexpected `name=` type {type(name)}; expected `str` or `Sequence[str]`')
 
         try:
             value = func(*args, **kwargs)
@@ -151,8 +150,8 @@ def _format_name(name: str) -> str:
 
         if isinstance(name, list) and (value.ndim != 2 or value.shape[0] != len(name)):
             raise ValueError(
-                f'The number of `name` elements ({len(name)}) must agree with the nubmer '
-                f'of arrays ({value.shape[0]}) the indicator returns.')
+                f'Length of `name=` ({len(name)}) must agree with the number '
+                'of arrays the indicator returns ({value.shape[0]}).')
 
         if not is_arraylike or not 1 <= value.ndim <= 2 or value.shape[-1] != len(self._data.Close):
             raise ValueError(