Enum.HasFlag implementation

Enum.HasFlag.cs

[System.Security.SecuritySafeCritical]
public Boolean HasFlag(Enum flag) {
    if (flag == null)
        throw new ArgumentNullException("flag");
    Contract.EndContractBlock();

    if (!this.GetType().IsEquivalentTo(flag.GetType())) {
        throw new ArgumentException(Environment.GetResourceString("Argument_EnumTypeDoesNotMatch", flag.GetType(), this.GetType()));
    }

    return InternalHasFlag(flag);
}

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