@Override
        public Builder flattenMixins() {
            if (getMixins().isEmpty()) {
                return this;
            }
            members(NamedMemberUtils.flattenMixins(members.get(), getMixins(), getId(), getSourceLocation()));
            return (Builder) super.flattenMixins();
        }
Removes a member by name.

<p>Note that removing a member that was added by a mixin results in
an inconsistent model. It's best to use ModelTransform to ensure
that the model remains consistent when removing members.

@param member Member name to remove.
@return Returns the builder.
smithy-model/src/main/java/software/amazon/smithy/model/shapes/EnumShape.java