pydantic - protected attributes are incorrectly treated as fields

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Describe the Bug

from pydantic import BaseModel


class Foo(BaseModel):
    a: int
    _a: int

    def initialize(self):
        self._a = 1


foo = Foo(a=1) # error: Missing argument `_a` in function `Foo.__init__` [missing-argument]

in pydantic, an attribute prefixed with _ is not considered a field. this code works at runtime

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(Only applicable for extension issues) IDE Information

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